,nature's ,miracles  ,famili> ,talks on 
,sci5ce  ,,by  ,,eli%a ,,gray1 ,,ph4    
,d41 ,,ll4 ,d4  ,,vol4 ,i  ,_w-,build+ &
 ,life  ,,e>?1 ,,air1 ,,& ,,wat]  ,,new 
,,york  ,,=ds1 ,,h[>d1  ,,hulb]t        
,,copyright1 #ahii1  ,,by  ,,=ds1 ,,h[>d
  ,,hulb]t4  ,,! ,,m]%on ,,company      
,,press1 ,,rahway1 ,n4 ,j4              
,,cont5ts4   ,,*apt]                    
,,page  ,,introduction1                 
v      ,,e>?4     ,i4 ,,_w-,,build+ ,,& 
,,life1                            #a   
,,ii4 ,,lime/one1                       
#ab     ,,iii4 ,,coal1                  
#bb     ,,iv4 ,,slate ,,& ,,%ale1       
#ca     ,v4 ,,salt1                     
#cf      ,,air4     ,,vi4 ,,!           
,,atmosph]e1                            
#db     ,,vii4 ,,air ,,temp]ature1      
#ea     ,,viii4 ,,cl\d ,,=mation1       
#fj     ,,ix4 ,,cl\d ,,=mation          
7,cont9u$71                    #fi      
,x4 ,,w9d--,,:y ,,x ,,bl[s1             
#gi     ,,xi4 ,,w9d 7,cont9u$71         
#hh     ,,xii4 ,,local ,,w9ds1          

#ajj     ,,xiii4 ,,wea!r ,,pr$ictions1  
#aaj     ,,xiv4 ,,h[ ,,dew ,,is ,,=m$1  
#aae     ,,xv4 ,,hail/ones ,,& ,,sn[1   
#abd     ,,xvi4 ,,meteors1              
#abi     ,,xvii4 ,,! ,,sky ,,& ,,its    
,,color1                         #acd   
,,xviii4 ,,liquid ,,air1                
#adf      ,,wat]4     ,,xix4 ,,riv]s ,,&
 ,,floods1                              
#aeb     ,,xx4 ,,tides1                 
#afa     ,,xxi4 ,,:at ,,is ,a ,,sponge8 
#afg     ,,xxii4 ,,wat] ,,& ,,ice1      
#agg     ,,xxiii4 ,,/or$ ,,en]gy ,,9    
,,wat]1                       #ahb      
,,xxiv4 ,,:y ,,does ,,ice ,,float8      
#aib     ,,xxv4 ,,glaci]s1              
#aih     ,,xxvi4 ,,evid5ces ,,& ,,!ories
 ,,( ,,an ,,ice ,,age1          #bjg    
,,xxvii4 ,,glacial ,,& ,,preglacial     
,,lakes ,,& ,,riv]s1      #bag          
,,xxviii4 ,,"s ,,effects ,,( ,,!        
,,glacial ,,p]iod1          #bcj        
,,xxix4 ,,dra9age ,,be=e ,,! ,,ice      
,,age1                   #bci           
,,introduction4   ,de> ,read]3 ,please  

look ?r\gh ?is ,introduction be=e beg9n+
 ) ! regul> *apt]s4 ,x is always well to
 "k ! object1 aim1 & mode ( treatm5t ( a
 book be=e read+ x1 s z to be able to   
look at x f ! au?or's view-po9t4  ,fir/3
 ,a ^w ab\t ! title--,nature's          
,miracles4 ,"s may claim t x is         
unsci5tific to speak ( ! op]ations (    
nature z miracles4 ,b ! po9t ( ! title  
lies 9 ! p>adox ( f9d+ s _m wond]ful    
?+s--z wond]ful z any miracle t 0 ev]   
record$--subs]vi5t to ! rule ( law4  ,b1
 y say1 a miracle does n come "u any    
rule ( law4  ,ah6 are y sure ( t8 ,x is 
true t we may n und]/& ! law t ! s-call$
 miracle comes "u1 b ! ,au?or ( all     
natural law does4 ,we d n pret5d to     
dispute b t ! ,p[] t made nature's laws 
c *ange !m if ,he sees fit2 b we _c     
believe t ,he w ev] see fit4 ,x w\ld    
de/roy all ord] & h>mony1 all advancem5t
 9 sci5ce & k ( ,god's works1 n to be   
able to rely implicitly ^u ! laws (     
nature z consi/5t & cont9u\s4  ,9 putt+ 
out ^! little volumes1 x is n to be     

und]/ood t ! subjects treat$ w be m ?an 
t\*$ ^u1 at ! mo/ sali5t po9ts4 ,to d   
mu* m w\ld require volumes ( imm5se     
size1 & life w\ld be too %ort = me to   
write or = y to read !m4  ,aga93 ^!     
volumes are famili> talks4 ,! ,au?or    
wi%es to sit d[n ) y--s to speak--& n   
hold y at arm's l5g?4  ,x w be 8 aim to 
use ! language ( common life & to avoid 
all te*nical names s f> z possible1 or1 
:5 !y are necess>y1 to expla9 _! mean+4 
,! object is to rea* ! ?\s&s ( read]s :o
 h n & _c h ! advantages ( a sci5tific  
education1 b :o c by ?is means get at   
lea/ a rudim5t>y idea ( "s ( ! natural  
laws ) :i* !y are com+ 9 contact e h\r1 
& ?r\gh :i* ! inn] man has con/ant      
communication ) ! out] _w4 ,x may be1   
too1 t _m "y /ud5ts w be help$ by ^!    
pla9 g5]al views ( topics :i* _!        
text-books w give !m 9 detail4  ,a k ( !
 real ?+s 9 ! objective _w ab\t u & !   
laws t gov]n !m 9 _! int]-relations is (
 practical value to e man1 :atev] 8     
call+ may be4 ,n only w x be ( value    

practically1 b x w also be a con/ant    
s\rce ( int]e/ & pleasure4 ,man is s    
con/itut$ t he mu/ h some?+ to be       
int]e/$ 91 & if he has no res\rces )9   
himself he looks else:]e1 & (t5 to 8    
hurt1 m5tally1 morally1 or o!rwise4 ,if 
he c\ld h an int]e/ awak5$ 9 him = !    
/udy & contemplation ( ! natural _w he  
w\ld !n h a book to read t is always    
op51 always fre%1 always new4 ,he is    
deal+ ) facts & n !ory1 except z he uses
 !ory = gett+ at facts4  ,a man :o is   
all !ory is l a rudd]less %ip on a      
%oreless sea4 ,all he really kn[s is t  
he is afloat1 & if he l&s at all x is   
likely to be 9 an insane asylum4 ,! m9d1
 9 ord] to keep its balance1 mu/ h !    
solid f\ndation ( real ?+s4 ,!ories &   
speculations may be indulg$ 9 ) safety  
only s long z !y are bas$ on facts t we 
c g back to at all times & "k t we are  
on solid gr\nd4  ,x is ! desire & aim ( 
all good m5 to make _! nation a truly   
great p1 ) a civilization ! highe/      
possible4 ,! "* ( all k9ds ( gr[? is    

l>gely det]m9$ by ! "* ( ! mat]ial ^u   
:i* x fe$s4 ,! /udy ( natural law c nev]
 be h>mful1 b is always b5eficial1 = !  
/ud5t is !n work+ 9 h>mony ) law4 ,x is 
! violation ( law t makes all ! tr\ble 9
 ! _w--:e!r physical1 moral1 or social4 
,:5 we speak ( natural law we d n conf9e
 ourselves to :at is commonly kn[n z    
*emi/ry & physics1 & ! laws t gov]n !   
mat]ial _w1 b include z well ! laws (   
our own be+1 z intellectual & spiritual 
units4 ,= all law1 physical1            
intellectual1 & spiritual1 is 9 a s5se  
natural4  ,all dep>tm5ts ( sci5ce are   
simply bran*es ( "o great sci5ce1 & all 
phases ( human activity are t\*$ by x4  
,! prea*] is a bett] prea*]1 ! doctor a 
bett] doctor1 ! lawy] a bett] lawy]1 !  
editor a bett] editor1 ! bus9ess man a  
bett] m]*ant1 & ! me*anic a bett]       
workman1 if !y foll[ sci5tific me?ods4  
,inde$1 any man w be a bett] husb&1     
fa!r1 & citiz51 if he has "s tru/wor?y k
 ( ! laws "u :i* ?is great univ]se1 d[n 
to 8 own little "p ( x1 lives1 moves1 & 

has its be+4     ,,nature',s ,,miracles4
     ,,e>?4     ,,*apt] ,i4             
,,_w-,,build+ ,,& ,,life4   ,9 ! beg9n+ 
,god creat$ ! heav5 & ! e>?4 ,& ! e>? 0 
)\t =m1 & void4  ,:atev] our            
speculations may be 9 reg>d to a beg9n+1
 & :5 x 01 x is writt5 9 ! rocks1 t1 l !
 animals & plants ^u its surface1 ! e>? 
itself grew2 t = c\ntless ages1 measur$ 
by ye>s t no man c numb]1 ! e>? has be5 
gradually assum+ its pres5t =m &        
composition1 & t ! processes ( gr[? &   
decay are active e h\r4  ,! sci5ce t    
deals ) ! =mations & /ratifications t   
are f\nd on ! e>? & "u ! e>?1 & all !   
=ces t h be5 & are n[ active 9 _!       
=mation1 is call$ ,geology 7e>? sci5ce74
 ,x is a sci5ce ab\t :i* little is kn[n 
by ! av]age individual1 & yet x is "o ( 
transc5d5t int]e/1 f ! /udy ( :i* ! lov]
 ( nature c obta9 a va/ am\nt ( pr(it & 
pleasure4 ,:5 ! uncultur$ man sees a    
/one 9 ! road x tells him no /ory o!r   
?an ! fact t he sees a /one & t x w\ld  
bett] be remov$2 & all ! satisfaction he

 gets out ( x is 9 ! ?\ght t he has sav$
 "s unlucky wagon :eel f be+ wr5*$ or   
brok54 ,! sci5ti/ look+ at ! same /one  
p]haps w /op1 & ) a hamm] break x op51  
:5 ! newly expos$ faces ( ! rock w h    
writt5 ^u !m a hi/ory t is z real to him
 z ! pr9t$ page4 ,he is c>ri$ back to a 
f>-(f "t1 :]e he sees ! processes & =ces
 at "w t h =m$ ?is /one & made x :at x  
is1 n only 9 its outw>d =m1 b 9 its     
con/itution1 d[n to its molecules &     
atoms4 7,! ^w atom is us$ 9 *emi/ry to  
mean ! smalle/ p>ticle ( an elem5t>y    
sub/ance t w comb9e ) ! atoms ( ano!r   
sub/ance to =m new comp\nds ( matt]4 ,& 
molecules are made up ( atoms47 ,!      
sci5ti/ look+ at ?is /one sees 9 x n    
only t me*anical & *emical ag5cies h    
coop]at$ 9 ! "w ( its =mation1 b t      
animal life itself may h be5 ! *ief     
ag5cy 9 br++ ! mat]ials toge!r & giv+ =m
 to ! peculi> ar*itecture employ$ 9 its 
=mation4 ,if x is a piece ( lime/one ?is
 latt] /atem5t w be em95tly true4  ,"h  
is a p[]ful motive = ! /udy ( physical  

sci5ce4 ,x is n to be expect$1 nor is x 
possible1 t e individual c be a sci5ti/ 
9 ! /rict s5se ( ! ^w1 b x is possible =
 ev]yone ( ord9>y intellig5ce to become 
famili> ) ! sali5t facts ( sci5ce1 if   
only a small portion ( ! "t t is n[     
devot$ to ! read+ ( lit]ature t is r    
h>mful ?an helpful be sp5t 9 /udy+ !    
ph5om5a & works ( nature4  ,! acquirem5t
 ( su* k w\ld furni% e individual ) a   
con/ant s\rce ( in/ructive amusem5t t   
w\ld nev] lose its int]e/4 ,he w\ld n be
 dep5d5t e h\r ^u p & ?+s outside (     
himself2 because he w\ld c>ry ab\t ) him
 inexhau/ible s\rces ( in/ruction &     
pleasure t w\ld furni% him cont9ual &   
helpful div]sion & save him f a ?\s&    
morbid t5d5cies t are always ready to   
seize ^u an unemploy$ m9d4 ,!re are _m  
m5 & wom5 9 ! insane asylum to-day = !  
simple reason t !y h n made intellig5t  
use ( ! m5tal p[]s t nature has end[$ !m
 )4  ,s]mons are n always prea*$ f      
pulpits4 ,!y are writt5 9 ! rocks & on !
 fl[]s ( ! field & ! trees ( ! =e/4     

,let u !n look a little at ! und]gr\nd  
f\ndation ( all ?is beautiful e>?4 ,&   
be=e attempt+ t1 ! "q may arise 9 "s    
m9ds h[ we "k :at is s deep d[n "u !    
surface4 ,=tunately ?is is a "q v easily
 answ]$4 ,at "s p]iod aft] ! rocks 7 =m$
 ! cru/ ( ! e>? 0 brok5 by volcanic     
eruptions at v>i\s places & times1 &    
turn$ up1 z 9 ! =mation ( m\nta9s1 s t !
 edges ( ! v>i\s /ratifications ( !     
rocks1 f ^? ne> ! surface d[n to ! l[e/ 
rocks1 are expos$ to view4 ,ano!r means 
( kn[+ :at ! v>i\s =mations are has be5 
by bor+s ( deep wells4 ,^! bor+s1 h[ev]1
 are only confirmatory ( :at 0 well kn[n
 be=e ?r\gh ! upheavals t are pl5tiful 9
 all p>ts ( ! _w4 ,!re is abundant      
evid5ce t all ( ! rocks & all ( ! /rata 
( e "n & nature 7except p]haps igne\s   
rocks7 7 orig9ally laid d[n 9 wat]4 ,?is
 is evid5c$ n only by ! /ratifications  
!mselves1 b by ! evid5ces ( sea-life    
ev]y:]e pres5t 9 ! e>?'s cru/4 ,be=e !  
upheavals 9 ! e>?'s cru/ began1 ! :ole  
surface ( ! globe 0 a great ocean ( hot 

wat]4 ,! sub/ances ( :i* ! rocks 7 =m$ 7
 und\bt$ly held 9 susp5sion 9 ! air & 9 
! wat]1 & by a gradual process 7        
deposit$ 9 ! bottom ( ! ocean 9 lay]s1  
=m+ rocks ( v>i\s k9ds1 accord+ to !    
nature ( ! sub/ance deposit$4 ,gradually
 ! cru/ ( ! e>? 0 built up until x      
acquir$ a c]ta9 ?ickness2 :51 ei!r f    
%r9kage "u ! cru/ a great void 0 =m$    
until x c\ld n su/a9 its own weight1 or 
! pressure caus$ by conf9$ gases & molt5
 matt] produc$ an upheaval :i* broke !  
cru/ ( ! e>? outw>d1 caus+ great wr9kles
 t we call m\nta9 ranges4 ,und\bt$ly bo?
 =ces 7 active 9 produc+ ^! results4 ,:5
 ! gases & molt5 matt] _h escap$ ?r\gh !
 rifts 9 ! rocks caus$ by ! upheaval !re
 mu/ h be5 great voids =m$ t 7 fill$ up 
by ! %r9kage ( ! e>?1 caus+ mu*         
irregul>ity 9 its surface4  ,9 "s places
 !re 7 enorm\s elevations1 & 9 o!rs     
correspond+ly deep depressions4 ,! wat] 
t be=e 0 ev5ly di/ribut$ ov] ! surface (
 ! globe1 aft] ! upheavals ran (f into !
 l[] levels1 fill+ up ! great valleys1  

=m+ ! seas1 & leav+ ab\t "o-?ird ( ! l& 
surface uncov]$4 ,x mu/ n be suppos$1   
h[ev]1 t ! appe>ance ( ! l& 0 caus$ by  
"o gr& movem5t or upheaval1 b t x has   
be5 go+ on 9 successive /ages ?r\gh long
 ages ( "t4 ,?is is cle>ly evid5c$ by ! 
rock =mations4 ,! deposition ( rock     
/rata is /ill active 9 ! bottoms ( !    
oceans1 al?\gh n to ! same degree z 9   
=m] times4 ,:5 ! upheaval took place !  
old /ratifications 7 ?r[n out ( level1 b
 ! new ones t 7 !n =m$ rema9$ 9 a level 
position until !y 7 9 _! turn di/urb$ by
 "s subsequ5t upheaval4  ,! laws (      
gravitation w\ld t5d to precipitate !   
matt] held 9 susp5sion by ! wat] /raight
 d[n to ! bottom1 t[>d ! c5t] ( ! e>?1 s
 t ! plane ( ^! /ratifications w\ld t5d 
to be p>allel to ! surface ( ! wat]1 t  
is horizontal1 until di/urb$4 ,!n !y    
w\ld be tilt$ 9 _m directions4 ,h5ce x w
 be easily se5 :y ! seams 9 ! rocks1    
especially 9 & ne> m\nta9\s regions1 d n
 lie 9 a horizontal position aft] an    
upheaval1 b are f\nd /&+ at all angles1 

up to a p]p5dicul>4  ,view$ f ?is       
/&po9t1 ! solid portion ( ! old _w has  
gone all to pieces4 ,:]ev] !re is a *a9 
( m\nta9s x m>ks a breakage 9 ! e>?'s   
cru/1 & ^! m\nta9s are n all on ! l&1 b 
ext5d "u ! seas s deeply t !y are unable
 to lift _! heads above ! surface ( !   
wat]4 ,! e>? is no long] r\nd1 except 9 
g5]al outl9e1 b brok5 up into all sorts 
( %apes t give ! v>i$ conditions (      
l&scape t we f9d :i*ev] way we turn4    
,!re are b few volcanoes t are active 9 
?is age1 :ile 9 =m] times !y ext5d$ =   
?\s&s ( miles4 ,we /ill h occasional    
e>?quakes1 b und\bt$ly !y are v slight z
 comp>$ ) ^? t %ook ! e>? millions (    
ye>s ago4  ,if1 n[1 we /udy !           
con/itution ( ! e>?'s cru/ s f> z x has 
yet be5 p5etrat$1 we f9d x divid$ up    
into p]iods call$ ,prim>y1 ,second>y1 & 
,t]ti>y4 ,! prim>y p]iod rea*es d[n to !
 l9e :]e ! l[e/ =ms ( animal fossils    
beg9 to be f\nd4 ,?is is call$ !        
,paleozoic p]iod1 :i* means ! p]iod (   
anci5t life4 ,f "h let u fir/ g d[nw>d4 

,imm$iately "u ?is lies a /ratum (      
,metamorphic rocks4 ,to metamorphose is 
to *ange2 & metamorphic rocks are ^? :i*
 h be5 *ang$ by heat or pressure f _!   
orig9al =mation4 ,?is class ( rocks lie 
on top ( :at are call$ ,igne\s rocks1   
:i* means t !y h be5 =m$ by or subject$ 
to heat4 ,all lava-=m$ rocks are igne\s4
 ,!y are un/ratifi$1--n 9 lay]s or      
/rata1 b 9 a =mless mass1--& 9 ?is !y   
diff] f wat]-=m$ rocks4  ,if !re is a   
molt5 c5t] to ! e>? ^! igne\s rocks are 
und\bt$ly ! (fspr+ ( ?is great int]nal  
furnace4 ,! metamorphic rocks 7 prim>ily
 igne\s & are *ang$ some:at 9 _!        
/ructure by ! lapse ( "t4 ,= in/ance1   
m>ble is a metamorphic lime/one4 ,!     
diff]5ce betwe5 common lime/one & m>ble 
is 9 its molecul> /ructure--! way 9 :i* 
its smalle/ p>ticles are put toge!r4 ,!y
 are bo? c>bonates ( lime4 ,b ! m>ble is
 made up ( little cry/als & w take a    
poli%1 :ile ord9>y uncry/alliz$ lime/one
 w n4 ,! igne\s rocks are *iefly        
granite2 & granite is =m$ (             

or?oclase-feldsp>1 mica1 & qu>tz4 7,! ^w
 or?oclase means /raight fracture1 & !  
or?oclase-feldsp> has two l9es (        
cleavage at "r angles to ea* o!r47 ,?is 
is ! ord9>y composition ( granite1 b !re
 are a great _m v>iations1 *iefly z to  
color & proportions ( ! +r$i5ts nam$4   
,! igne\s rocks1 !n1 are ! l[e/ ( all2  
!n come ! metamorphic rocks2 & z be=e   
/at$1 on top ( metamorphic rock beg9s ! 
fir/ evid5ce ( life 9 its l[e/ =m4 ,!   
,paleozoic 7anci5t life7 or ,prim>y     
p]iod is made up ( a numb] (            
subdivisions4 ,! fir/ & olde/ division  
is call$ ! ,silurian age1 :i* is        
und]laid by ! metamorphic rocks &       
ov]laid by ! rocks ( ! ,devonian p]iod4 
,x is call$ ,silurian1 f ! "n ( a k9d ( 
fi%1 fossils ( :i* are f\nd 9 ! rocks ( 
?is age1 :i* are di/+ui%$ = ! abs5ce (  
l&-plant fossils & v]tebrate animals4   
,9 ! ,silurian /rata are f\nd lime/ones1
 slate1 flag/ones1 %ales1 etc4 ,on top (
 ! ,silurian beg9s ! ,devonian age1 9   
:i* is f\nd ! old r$ s&/one1 z well z   

lime/one & slate2 & "h beg9 to be f\nd !
 fossils ( l&-plants4 ,on top ( !       
,devonian lies ! ,c>bonif]\s s]ies1 :i* 
complete ! s]ies ( ! prim>y p]iod4 ,9 ! 
l[] "p ( ?is /ratum is f\nd c>bonif]\s  
lime/one1 :i* is ov]laid by a k9d ( /one
 call$ mill/one grit1 & on top ( ?is lie
 ! true c>bonif]\s /rata or coal-be>+   
measures4 ,9 ! coal /rata are f\nd !    
fir/ reptile fossils4  ,on top ( ! coal 
measures beg9s ! ,second>y p]iod1 or    
,mesozoic 7middle life74 ,?is p]iod is  
di/+ui%$ = ! great developm5t (         
reptiles1 & is call$ ! age ( reptiles4  
,9 ?is age occur ! fir/ traces (        
mammals1 & birds1 & fi%es ) bony        
skeletons4 ,among plants we f9d "h !    
fir/ evid5ce ( palms4 ,! =mation is     
*iefly *alk1 s&/ones1 clays1 lime/one1  
etc4 ,we n[ come to ! la/ or ,t]ti>y    
p]iod1 :i* br+s u to ! top e>?4 ,?is is 
*iefly =m$ ( s$im5t>y rocks--^? :i* h   
be5 =m$ by ! settl+ ( s$im5t1 9 wat]4   
,:ile we are =c$ to ^! g5]al conclusions
 9 reg>d to ! build+ ( ! _w1 & to its   

subsequ5t di/ortion by ! s]ies (        
upheavals t h occurr$ f "t to "t1 & to !
 successive ages ( ! lay]s ( rock       
f\ndation ( its cru/1 !re are _m my/]ies
 t rema9 unsolv$ & _m que/ions w pres5t 
!mselves to ! m9d ( ! read]4 ,"o ( ^!   
que/ions is1 ,:]e 0 ! wat] & :]e 0 !    
e>?y matt] be=e its precipitation8      
,matt]1 includ+ wat]1 c exi/ 9 ! gase\s 
=m1 & we only ne$ to assume t !re 0 a   
core ( int5se heat1 to und]/& h[ all !  
mat]ial t we f9d on ! e>? & 9 ! e>? c\ld
 h be5 held 9 susp5sion 9 ! gase\s /ate 
until ! cool+ process _h rea*$ a /age   
:]e ! v>i\s comb9ations & recomb9ations 
c\ld take place 9 ! great laboratory (  
nature4 ,if we /udy ! con/itution ( !   
sun 7& ) ! mod]n appliances we are able 
to d s71 we f9d t x is made up ( "s &   
p]haps all ( ! same mat]ials t are f\nd 
"h on e>?4 ,if !re is no wat] exi/+1 9 !
 sun1 z wat]1 !re are ! gases pres5t :i*
 w\ld produce x if ! conditions 7 "r4   
,&1 = all we "k1 t flam+ mass ( burn+   
gases may "s "t g ?r\gh ! same k9d (    

cool+ & build+ up 9 solids t our e>? has
 exp]i5c$4  ,we ?us h :at may be call$  
an outl9e sket* ( ! process (           
,_w-build+4     ,,*apt] ,,ii4           
,,lime/one4   ,a l>ge "p ( ! /ructure ( 
! e>?'s cru/ is =m$ ( a sub/ance call$  
lime/one4 ,ord9>y lime/one is a comp\nd 
( common lime & c>bon dioxide1 a gas t  
is f\nd mix$ ) ! air to a v small       
degree4 ,c>bon dioxide w be bett] kn[n  
by ! old] p z c>bonic acid4 ,x is a gas 
t is giv5 (f :5ev] wood & coal are      
burn$1 or any sub/ance conta9+ c>bon4 ,x
 is compos$ ( "o atom ( c>bon to two (  
oxyg54 ,e ton ( coal t is burn$ s5ds (f 
?ree & two-?irds tons ( ?is gas4 ,!     
increase 9 weight comes f ! fact t e    
atom ( c>bon unites ) two ( oxyg51 :i* x
 takes f ! air1 & ! oxyg5 is heavi] ?an 
! c>bon4  ,9 comp>+ ! relative weights (
 atoms 7! smalle/ comb9able p>ticle ( a 
solid1 liquid1 or gas7 we use ! hydrog5 
atom z ! unit ( comp>ison & call x "o1  
because x is ! lighte/ ( all atoms4 ,!  
c>bon atom is twelve times heavi] ?an ! 

hydrog5 atom1 & ! oxyg5 atom is sixte5  
times heavi]4 ,h5ce x w be se5 readily  
h[ a ton ( coal w =m two & two-?irds    
times its weight ( c>bonic dioxide4     
,lime1 hav+ a /rong aff9ity or          
attraction = ?is gas1 has absorb$ x f ! 
air & wat]1 =m+ :at is kn[n z c>bonate (
 lime--:i* is ! ord9>y lime/one4 ,*alk &
 ! v>i\s m>bles are also c>bonates (    
lime4 ,lime/one /rata 9 ! cru/ ( ! e>?  
are f\nd 9 all ! p]iods ( ! e>?'s       
=mation4 ,all =ms ( sea %ells t 7 once !
 homes ( animal life are con/ruct$ ( ?is
 comp\nd2 & 9 ! lat] =mations (         
lime/one1 9 ! ,second>y & ,t]ti>y       
p]iods1 we f9d ?is rock to be made up   
almo/ entirely ( m>9e %ells1 "s ( !m    
microscopic 9 size4 ,! e>li] or old]    
=mations ( lime/one t are f\nd deep] d[n
 9 ! e>?'s cru/ are less m+l$ ) ^! m>9e 
%ells4 ,?is comes f ! fact t ! fir/     
deposition ( lime/one /rata occurr$ be=e
 ! lat] =ms ( sea life _h develop$4     
,:atev] signs ( life are f\nd 9 ^! l[]  
/ratifications are ( ! v l[e/ ord]4 ,x  

is n to be und]/ood t animal life is a  
necess>y factor 9 ! =mation ( lime/one1 
b x has be5 an incid5tal feature :i* no 
d\bt has be5 ! *ief means ( ga!r+ up f !
 wat] ?is comp\nd & precipitat+ x into !
 great lime/one /rata t are ev]y:]e     
f\nd4  ,c>bonate ( lime is f\nd 9       
solution 9 ne>ly1 if n q1 all ( ! m9]al 
wat]s1 & is also f\nd 9 ! wat] ( !      
ocean4 ,9 e>li] times x mu/ h be5 held 9
 solution 9 mu* great] quantities ?an at
 pres5t4 ,! myriads ( sea animals t     
exi/$1 & t /ill exi/1 ga!r$ f ! wat] ?is
 sub/ance1 :i* =m$ _! %ells1 & s]v$ z a 
h\se 9 :i* !y liv$4 ,new g]ms 7         
cont9ually =m+ new %ells1 :ile ! old]   
ones ceas$ to live z animals1 & _! h\ses
 9 :i* !y liv$ 7 precipitat$ to ! bottom
 ( ! ocean1 :]e !y 7 b\nd toge!r z      
lime/one rock4 ,^! sea animals no d\bt  
caus$ a mu* m rapid =mation ( lime/one  
?an w\ld or c\ld h be5 ! case )\t _!    
exi/5ce4  ,"o c ?us readily see :at an  
important factor animal life has be5 9 !
 process ( _w-build+4 ,?is process is   

/ill go+ on1 b probably n to ! same     
ext5t z 9 =m] ages1 because x is n      
likely t !re is s mu* c>bonate ( lime   
held 9 solution z !re 0 be=e ^! great   
lime/one b$s 7 =m$4 ,lime/one1 h[ev]1 is
 easily dis9tegrat$ by ! action ( wat]4 
,we f9d ! spr+ wat] impregnat$ ) x z    
well z t ( ! small /reams & riv]s4 ,pure
 wat] is a p[]ful solv5t4 ,:5 ! ra9s    
fall ^u ! e>? ! wat] p]colates ?r\gh x &
 ?r\gh ! lime/one /rata1 :i* gradually  
we>s away ! lime/one & c>ries x back to 
! ocean1 s t ! process ( te>+ d[n &     
build+ up is cont9ually go+ on4 ,! great
 caves t are f\nd ev]y:]e 9 ! lime/one  
regions 7 =m$ by ! action ( wat]4 ,!    
great ,mammo? ,cave ( ,k5tucky1 :i* is  
said to h #bjj miles ( und]gr\nd        
passages1 has be5 entirely worn out by !
 action ( runn+ wat]4  ,"s ye>s ago !   
writ] visit$ ?is cave & _h an           
opportunity to /udy ! wond]ful erod+ or 
gnaw+-out effect ( wat] on lime/one4 ,at
 "s p]iod e>li] 9 ! hi/ory ( ! e>? !re 0
 evid5tly an und]gr\nd riv] or l>ge     

/ream ( wat] t f\nd its way ?r\gh !     
crevices ( ! rocks1 & gradually wore out
 a great b$ = itself1 :i* 0 f$ by lat]al
 /reams p\r+ into ! ma9 bran*1 ea* "o ( 
:i* lat]al bran*es cut its own *annel4  
,a plan view ( ! ,mammo? ,cave pres5ts a
 picture n unlike t ( a great riv] )    
num]\s bran*es empty+ into x1 all ( !m  
%[+ ! w9d+s su* z we see 9 a riv] & its 
fe$]s ^u ! surface ( ! e>?4 ,!re are    
?ree sets ( ^! *annels1 "o above ! o!r1 
& we d n f9d ! wat] till we get to !    
bottom ( ! ?ird und]gr\nd /ory1 s to    
speak4 ,!re is "o place 9 ?is sy/em (   
und]gr\nd *annels :]e ! dripp+ f ! ro( (
 ! upp] *annels has cut a great well    
hole _m feet 9 diamet] p]p5dicul>ly d[n 
?r\gh ! :ole sy/em to a great dep?4 ,!  
sides ( ?is great well hole are flut$   
into grooves caus$ by ! con/ant d[nfl[ (
 ! wat]4 ,al?\gh ! am\nt ( wat] fl[+ d[n
 ?r\gh ?is well hole is v small1 x is   
cont9ually at "w4 ,l int]e/ on money1 x 
nev] re/s1 ea* m9ute t passes has eat5  
away "s ( ! great rock4  ,9 o!r portions

 ( ! cave ! dripp+ ( ! wat] is s gradual
 t ! c>bonate ( lime h>d5s & =ms :at are
 call$ /alactites1 t hang l icicles f ! 
ro( ( ! cave4 ,sometimes ! wat] runs d[n
 s sl[ly ^u ^! /alactites t x evaporates
 z fa/ z x appe>s1 leav+ beh9d its      
little load ( c>bonate ( lime4 ,if1     
h[ev]1 !re is a drip1 !re are =mations  
built also f ! lime 9 ! dropp+ wat] on !
 floor ( ! cave1 & ^! are call$         
/alagmites4 ,9 "t ! /alactites & !      
/alagmites w meet1 =m+ a great column   
rea*+ f floor to ceil+4 ,"s ( ^!        
=mations1 :5 !y are free f =eign        
sub/ances1 are v beautiful4 ,!y are also
 v h>d1 giv+ (f a metallic musical tone 
:5 /ruck by any h>d sub/ance4  ,we h    
already /at$ t lime/one is a comp\nd (  
ord9>y lime & c>bon dioxide1 =m+ a      
c>bonate ( lime4 ,?is /atem5t does n    
give a complete analysis ( all ! elem5ts
 ent]+ into lime/one4 ,9 ! fir/ place   
lime itself is a comp\nd =m$ ( two      
elem5t>y sub/ances1 calcium & oxyg54 ,! 
lime molecule is compos$ ( "o atom (    

calcium & "o ( oxyg54 ,nei!r calcium nor
 lime is f\nd pure 9 nature4 ,inasmu* z 
c>bon dioxide is compos$ ( "o atom (    
c>bon & two ( oxyg51 & lime is compos$ (
 "o atom ( calcium & "o ( oxyg51 :5 we h
 ! two comb9$ ! molecule ( c>bonate (   
lime1 or1 z x is te*nically call$1      
calcic c>bonate1 is compos$ ( "o atom ( 
calcium1 "o ( c>bon & ?ree ( oxyg51     
7lime plus c>bon dioxide74  ,z be=e     
/at$1 lime is n f\nd un-comb9$ ) o!r    
sub/ances 9 nature4 ,& z x is ( great   
economic importance1 x w be pr(itable to
 "k h[ x is =m$4 ,lime is produc$ f     
ord9>y lime/one by burn+ x 9 kilns :]e x
 is subject$ to a heat ( a c]ta9        
temp]ature = a numb] ( h\rs4 ,! heat    
drives (f ! c>bon dioxide1 :i*1 z we h  
se51 has tak5 away f ea* molecule ( !   
comp\nd all ( ! c>bon & two atoms ( !   
oxyg51 :ile all ( ! calcium is reta9$ ) 
"o atom ( oxyg51 leav+ ord9>y lime4     
,lime1 !n1 is simply oxide ( calcium4   
,z all "k1 x is us$ almo/ exclusively = 
mak+ mort> = build+ purposes4 ,9 ord] to

 d ?is we h to put x ?r\gh ! process (  
slack+1 by p\r+ wat] ^u x1 & "h ano!r   
*emical *ange takes place4 ,! wat]      
unites ) ! lime1 :5 imm$iately ! heat t 
0 exp5d$ 9 ?r[+ (f ! c>bon dioxide & 0  
/or$ 9 ! lime z en]gy is n[ giv5 up aga9
 9 ! =m ( heat4 ,:5 a consid]able bulk (
 lime is slack$ v rapidly ! heat t is   
giv5 (f is s great t x w produce        
combu/ion4 ,"h is a beautiful           
illu/ration ( :at has be5 errone\sly    
call$ lat5t heat4 ,x is heat /or$ z     
pot5tial en]gy1 t is releas$ by !       
comb9ation ( lime ) wat]4 ,slack5$ lime1
 !n1 is call$ calcic hydrate4  ,v little
 ( ! lime/one t we f9d is absolutely    
pure4 ,x is consid]$ good :5 x does n   
conta9 ov] five or six p] c5t4 ( =eign  
sub/ance4 ,:5 m ?an ?is is pres5t ! lime
 is consid]$ poor1 & :5 x rea*es fifte5 
p] c5t4 or m ( impurities x assumes !   
prop]ty ( h>d5+ "u wat] & is call$      
cem5t4  ,c>bonate ( lime is f\nd 9      
sev]al o!r =ms2 = in/ance1 ! v>i\s k9ds 
( m>ble & *alk are c>bonates ( lime4 ,! 

composition ( m>ble & *alk is exactly ! 
same z t ( lime/one4 ,! diff]5ce is     
*iefly "o ( molecul> r ?an *emical      
/ructure4 ,m>ble is :at *emi/s w\ld call
 an allotropic or *ang$ =m ( lime/one2  
&1 z be=e /at$1 ! diff]5ce seems to     
consi/ 9 ! fact t ! m>ble assumes a     
cry/all9e arrangem5t ( its atoms & w    
!re=e take a high poli%1 :i* is n true (
 ord9>y lime/one4 ,m>ble v>ies greatly 9
 color+ & texture1 all ( :i* diff]5ces  
are expla9able "u ! "o head ( molecul>  
arrangem5t4 ,ne>ly pure c>bon exi/s 9   
?ree di/9ct =ms--! diamond1 graphite1 & 
*>coal4 ,z is ! case ) m>ble1 ^!        
diff]5ces 9 ! diff]5t =ms ( c>bon are n 
*emical1 b molecul> diff]5ces4 ,!       
sub/ances are ! same1 b _! inf9itesimal 
p>ticles are diff]5tly arrang$4         
,c>bonate ( lime--z x exi/s 9 its v>i\s 
=ms1 z lime/one1 f :i* lime & cem5t are 
made1 & m>ble1 :i* is su* an important  
elem5t 9 ! arts--is a sub/ance ( great  
importance to man4 ,we h already not$ "s
 ( ! processes t nature uses 9 ga!r+ up 

^! sub/ances f ! ocean by ! employm5t ( 
v>i\s =ms ( animal life4 ,"h is ano!r4  
,:oev] has visit$ ! ,b]mudas has se5 an 
isl& :olly =m$ ( :at is call$ coral     
rock4 ,coral is a /ructure produc$ by a 
peculi> =m ( sea animal t ga!rs up !    
calc>e\s or lime-l matt] float+ 9 ! sea 
wat]1 & builds a h\se ( x 9 :i* to live 
dur+ ! little lifetime t is allott$ to  
him4 ,:5 he dies 8 *ildr5 d n occupy !  
old home1 b build a new "o1 :i* is a    
sup]/ructure plant$ ^u ! old "o z a     
f\ndation4 ,?is process ( gr[? sometimes
 takes ! =m ( a tree or plant1 & coral  
trees gr[ ^u trees & plants ^u plants1  
until a /ructure is erect$ hav+ its     
f\ndation ^u ! bottom ( ! ocean1 t      
f9ally rea*es up until x rises above !  
surface ( ! wat]2 & "h--aft] ?r\gh ye>s 
! wat] has br\ght sea-we$ & drift to    
decay & =m soil1 & ! birds h br\ght se$s
 & f]tilization1 & vegetable life is    
prosp]+--ano!r animal call$ man builds 8
 home ^u x4 ,! mat]ial t ! coral is =m$ 
( is sub/antially ! same z t we f9d 9 ! 

m9ute %ells ( ! lime/one rocks4  ,!     
great *alk cliffs t are f\nd on ! coa/s 
( ! ,engli% *annel are ! "w ( a sea     
animal microscopic 9 size4 ,at "o "t x 0
 a "q among sci5ti/s h[ ^! *alk cliffs 7
 =m$1 b :5 ! microscope 0 inv5t$ ?is    
my/]y1 z well z _m o!rs1 0 solv$4 ,!    
*emical compon5ts ( *alk are precisely !
 same z ^? ( lime/one4 ,! microscope %[s
 t *alk is almo/ :olly a product ( v    
small organiz$ %ells4 ,! animals :o are 
! ar*itects ( ! *alk cliffs are call$   
=am9if]a--be>+ %ells p]=at$ ) little    
holes4 ,! *ief diff]5ce betwe5 *alk &   
lime/one seems to be 9 ! size ( ! %ells 
( :i* !y are respectively made up & 9 ! 
mann] ( ! bond+ ( ^! %ells toge!r4 ,!   
%ells 9 a lump ( *alk are held mu* m    
loosely ?an ^? 9 a lump ( lime/one4 ,^! 
intrepid work]s are /ill actively *ang+ 
! /ructure ( ! bottoms ( seas & oceans1 
& =m+ new isl&s1 :i* 9 turn become !    
sub/ructure t supports new life1 animal 
& vegetable4 ,& :5 we consid] ! great "p
 p]=m$ by ^! microscopic ar*itects &    

build]s x is n a misnom] to speak ( !   
build+ ( a _w4     ,,*apt] ,,iii4       
,,coal4   ,"s "t1 long ago1 "s man made 
! discov]y t :at we n[ call coal w\ld   
burn & produce light & w>m?4 ,:o he 0 or
 h[ long ago he liv$ we d n "k1 b z all 
e>?ly ?+s h a beg9n+1 we "k t su* a man 
did live & t ! discov]y t coal w\ld burn
 0 made4 ,coal1 9 ! s5se t we use ! ^w  
"h1 is n m5tion$ 9 ! ,scriptures4       
,accord+ to "s au?orities1 coal 0 us$ 9 
,engl& z e>ly z ! n9? c5tury4 ,x is     
record$ t 9 #abei ,k+ ,h5ry ,,iii4      
grant$ a privilege to c]ta9 p>ties to   
m9e coal at ,newca/le4 ,x is fur!r /at$ 
t sev5 ye>s aft] ?is "t coal became an  
article ( export4 ,9 #acjf coal 0 s     
g5]ally us$ 9 ,london t a petition 0 s5t
 to p>liam5t to h ! use ( x suppress$ on
 ! gr\nd t x 0 a nuisance4 ,coal 0 us$ 9
 ,belgium1 h[ev]1 ab\t #abjj4 ,!re is a 
tradition t a blacksmi? fir/ us$ x 9    
,liege z fuel4 ,x 0 fir/ us$ =          
manufactur+ purposes ab\t #agac4  ,coal 
is f\nd laid d[n 9 great ve9s1 v>y+ 9   

?ickness1 9 v>i\s p>ts ( ! _w 9 ! upp]  
/rata ( ! ,paleozoic p]iod4 ,! age 9 :i*
 x 0 =m$ is call$ by geologi/s !        
,c>bonif]\s 7coal-be>+7 age4  ,be=e go+ 
on to acc\nt = ! deposits ( coal1 let u 
/op a mom5t & consid] :at x is4 ,*emi/s 
tell u t coal is *iefly con/ruct$ (     
c>bon1 comp\nd$ ) oxyg51 hydrog51 &     
nitrog54 ,!re are _m v>ieties1 b all may
 be classifi$ "u two g5]al              
head+s--bitum9\s & an?racite4 ,bitum9\s 
coal conta9s a l>ge am\nt ( a t>ry      
sub/ance1 a k9d ( m9]al pit* or bitum51 
:i* burns ) a brilliant flame & a black 
sooty smoke1 exce$+ly ri* 9 c>bon4      
,an?racite coal is h>d & /one-l 9 its   
texture1 burn+ ) sc>cely any flame & no 
smoke4 ,x produces a fire ( int5se heat 
:5 x is once ignit$4 ,!re is ano!r =m ( 
coal call$ cannel coal1 :i* is a        
corruption ( c&le coal1 s call$ because 
a piece ( ?is k9d ( coal :5 ignit$ w    
burn l a mat* or p9e knot & give light l
 a c&le4 ,?is is ! ri*e/ ( all ! coal   
deposits 9 gases t are set free by heat1

 & = ?is reason is ext5sively us$ 9 !   
manufacture ( :at is commonly call$ coal
 gas4 ,engl& produces a l>ge am\nt (    
cannel coal1 z well z ano!r v>iety (    
bitum9\s coal1 :i* latt]1 h[ev]1 does n 
burn ) su* a black smoke z ! coal f\nd 9
 ! ,ohio valley & ! ,we/]n ,/ates (     
,am]ica4 ,ea/ ( ! ,alleghany ,m\nta9s   
!re is a region ( an?racite coal t is v 
ext5sively work$ & f9ds great favor 9   
all p>ts ( ! c\ntry z fuel = dome/ic    
heat+1 especially on acc\nt ( its great 
cleanl9ess4  ,all ( ! coal b$s h a      
common orig91 & ! diff]5ce 9 ! quality (
 coal f\nd 9 diff]5t p>ts ( ! c\ntry is 
due to _m circum/ances1 "s ( :i* h nev] 
be5 expla9$4 ,!re is indisputable pro(1 
h[ev]1 t all coal b$s are ( vegetable   
orig94 ,geologi/s tell u t ^! coal b$s 7
 =m$ dur+ an age be=e ! e>? _h cool$ d[n
 to ! temp]ature t x has at ! pres5t    
"t--an age :5 vegetation 0 =c$ by !     
int]nal heat ( ! e>? in/ead ( hav+ to   
receive all its w>m? f ! sun's rays z we
 d n[4 ,"s ( our read]s are famili> )   

:at is commonly t]m$ a hotb$4 ,a hotb$  
is made by putt+ soil on top ( sub/ances
 t w f]m5t & create heat und]nea? !     
soil4 ,?is heat f b5ea? w =ce vegetation
 & cause a mu* l>g] gr[? ?an !re w be if
 left to ! sun's rays alone4 ,dur+ !    
c>bonif]\s age ! e>? 0 a great hotb$4   
,! fossils ( trees & plants1 z well z   
reptiles1 t we f9d 9 ! great coal       
measures ( ! _w1 %[ t !y 7 ( l>ge       
tropical gr[?1 & ?is is %[n n only 9 !  
temp]ate zone1 b 9 ! zone f>!r nor?4 ,= 
ages & ages ?is rank gr[? ( vegetation  
grew up & fell d[n until a great lay] ( 
vegetable matt] 0 =m$1 :i* at a lat] "t 
0 cov]$ ov] by o!r /ratifications ( e>? 
mat]ial1 s t ^! great lay]s ( vegetable 
=mation 7 h]metically seal$ & press$ d[n
 by an enorm\s weight t increas$ z "t   
w5t on4 ,! =mation ( coal may be /udi$  
ev5 at ?is day 7= x is n[ go+ on7 by    
visit+ & exam9+ ! great peat b$s t are  
f\nd 9 v>i\s p>ts ( ! _w4 ,x is well    
kn[n t peat is us$ z a fuel by _m p1    
especially ! peasantry ( ! old c\ntries4

 ,if peat is press$ to a suffici5t      
degree ( h>dness x burns 9 a mann] n    
unlike "s =ms ( coal4 ,peat is a        
vegetable =mation & has be5 =m$ by !    
rank gr[? ( v>i\s k9ds ( vegetation 9   
swampy places4 ,( c\rse1 x lacks !      
purity ( ! coal t 0 =m$ dur+ !          
c>bonif]\s age1 because ( ! mu* sl[]    
gr[? ( vegetation n[ ?an dur+ t "t1 & ! 
opportunity t peat bogs (f] = an        
int]mixture ( e>?y ) ! vegetable matt]4 
,! fact t we f9d ! impr9t ( trees & f]ns
 & o!r vegetable gr[? ( tropical        
v>ieties1 z well z ! fossils ( reptiles1
 imb$d$ 9 ! coal measures1 proves t at  
"o "t ?is /ratum 0 at ! l& surface ( !  
e>?4 ,we also f9d t all ( ! =mations ( !
 ,second>y & ,t]ti>y p]iods are on top (
 ! coal--& ?is %[s t aft] ! age ( rank  
vegetable gr[? !re 0 a s9k+ ( ! e>? 9 _m
 places f> d[n into ! ocean--s t va/    
lay]s ( rock =m$ on top ( ^! b$s (      
vegetable matt]4 ,9 ,engl& great *alk   
b$s crop out 9 cliffs on ! s\!rn coa/1  
&1 z we h se51 ^! *alk rocks are l>gely 

made up ( ! %ells ( m>9e animals4       
,london /&s on a *alk b$1 f six hundr$  
to eight hundr$ feet ?ick4 ,inde$1      
,engl& has be5 poetically call$ ,albion1
 ,:ite-l&1 f ?is appe>ance ( h] coa/4   
,all ( ! great *alk b$s 7 =m$ ages aft] 
! coal b$s1 z ! latt] are f\nd 9 ! upp] 
/rata ( ! ,paleozoic p]iod4  ,a /udy (  
^! /rata w %[ t !re are _m lay]s ( coal 
/rata v>y+ 9 ?ickness & sep>at$ by lay]s
 ( %ale & s&/one4 ,h[ ! %ale & s&/one   
lay]s are =m$ w be ! subject ( a future 
*apt]4  ,f ! position t ! coal measures 
occupy1 be+ entirely "u ! ,second>y &   
,t]ti>y =mations1 x w be obs]v$ t !y are
 v old4 ,if we %\ld exam9e a piece (    
ord9>y bitum9\s coal we %\ld f9d t !re  
are l9es ( cleavage 9 x p>allel to ea*  
o!r1 & t x is an easy matt] to sep>ate !
 lump on ^! l9es4 ,if we exam9e !       
outcrop ( a coal b$ we w f9d t ^! l9es (
 cleavage are horizontal4 ,?is indicates
 t ! great bulk ( vegetable matt] ( :i* 
! coal =mation is made up has be5       
subject$ to trem5d\s pressure dur+ a    

long p]iod ( "t4 ,if we fur!r exam9e !  
/ructure ( a body ( coal we f9d !       
impressions ( limbs & bran*es z well z !
 leaves ( trees & v>i\s k9ds ( plants4  
,we %all fur!r f9d t ^! impressions lie 
9 a plant 9 ! same direction z ! l9e (  
cleavage4 ,?is is a po9t to be rememb]$1
 z x helps to expla9 ! nature & /ructure
 ( o!r =mations ?an ^? ( coal4 ,n only  
are leaves & bran*es ( vegetable matt]  
f\nd1 b fossils ( reptiles1 su* z live  
on ! l&4 ,sometimes !re is f\nd ! fossil
 ( a great tree trunk /&+ 9 an erect    
position1 ) its roots runn+ d[n into !  
rock bel[ ! coal b$1 :ile ! trunk ext5ds
 upw>d entirely ?r\gh ! coal & high up  
into ! o!r /rata4 ,all ( ^! facts lead u
 to ! firm conclusion t :5 ! trees 7    
gr[n t =m$ ^! b$s !y 7 above ! surface (
 ! ocean4 ,?is1 tak5 9 connection ) !   
fact t ! vegetable fossils t are f\nd   
indicate a tropical gr[? ( great size1  
drives u to ! conclusion t ! climate at 
! "t ^! coal measures 7 =m$ 0 mu* w>m]  
?an x is n[4  ,z already rem>k$1 ?is    

extra w>m? came f ! e>? itself be=e x _h
 cool$ d[n to its pres5t temp]ature1 r  
?an f ! heat ( ! sun4 ,!re is no?+      
inconsi/5t 9 ! ?\ght t ! sun may h be5  
w>m] 9 a =m] age ?an n[4 ,we may        
conceive t ! e>lie/ coal =mations took  
place :5 ! l& /ood above ! surface ( !  
wat]1 & t ! conditions 7 favorable = a  
rapid & luxuriant gr[? ( vegetation2    
aft] ?is _h gone on = a v long p]iod (  
"t1 by "s convulsion ( nature ! l&      
surface 0 subm]g$ "u ! ocean1 :5 o!r    
m9]al sub/ances 7 deposit$ on top ( ?is 
lay] ( vegetable gr[?1 :i* h>d5$ into a 
rock =mation4 ,at a lat] p]iod ! e>? 0  
aga9 elevat$ above ! surface ( ! wat] & 
! same process ( gr[? & decay 0 repeat$4
 ,^! oscillations ( ! e>? up & d[n      
occurr$ at enorm\sly long int]vals1     
until all ( ! v>i\s coal /rata ) _!     
int]m$iate =mations 7 complet$4 ,aft]   
?is we mu/ suppose t ! :ole 0 subm]g$ to
 a great dep? & = a v long p]iod ( "t1  
because ( ! great numb] & v>i\s k9ds (  
rock =mations laid d[n by wat] t lie on 

top ( ! coal measures4 ,?is trem5d\s    
weight1 z x 0 gradually build$ up1      
subject$ ^! vegetable /rata to an       
inconceivable pressure4 ,9 "s places ?is
 pressure 0 mu* great] ?an 9 o!rs1 :i*  
und\bt$ly is "o ( ! reasons :y we f9d   
su* diff]5ces 9 ! /ructure & quality (  
coal4 ,!re 7 no d\bt _m o!r reasons =   
diff]5ces1 "o ( !m be+ ! "* ( !         
vegetable gr[? out ( :i* !y 7 =m$4      
,aga91 9 "s p>ts ( ! _w ^! coal /rata   
may h be5 subject$ to a consid]able     
degree ( heat1 :i* w\ld *ange ! /ructure
 ( ! =mation1 & 9 "s cases drive (f !   
volatile gases4 ,"o c easily imag9e t   
heat 0 ?us a factor 9 ! =mation ( :at is
 kn[n z an?racite coal1 s mu* less      
gase\s ?an ! bitum9\s k9ds4 ,! an?racite
 b$s seem to be d5s] & ( a m homog5e\s  
"*4 ,! l9es ( cleavage are n z prom95t1 
b !re are ! same evid5ces ( vegetable   
orig9 t we f9d 9 ! bitum9\s =mations4   
,x w be se5 f :at has gone be=e t coal 0
 fir/ wood4 ,b wood is a product (      
sun%9e4 ,?us ! sun 0 ! ar*itect & build]

 ( ! trees & plants t 7 f9ally          
h]metically seal$ "u ! great e>? /rata4 
,! sun ga!r$ up ! mat]ial & set ! =ces 9
 play :i* made ! *emical comb9ations ( !
 v>i\s elem5ts 9 nature t ent] into     
vegetable gr[?4  ,aft] ! lapse ( untold 
ages ( "t ^! great b$s ( /or$-up        
sun-en]gy 7 discov]$ by man & _! cont5ts
 are dragg$ out to ! e>?'s surface1 to  
w>m our h\ses1 to drive ! ma*9]y ( our  
factories1 to s5d ! locomotives fly+    
across ! cont95ts & ! /eam%ips ov] !    
oceans4 ,s important has ?is article    
become t if any "o nation c\ld control !
 output x w\ld be able to p>alyze all ! 
navies & ! manufactur+ ( ! _w4  ,if !   
coal ( ! _w %\ld become exhau/$ we %\ld 
be confront$ ) a great problem4         
,=tunately = u1 ?is is a problem t w h  
to be solv$ by ! p ( "s future age1 z ! 
gr[? ( wood w sc>cely keep pace ) !     
consumption ( fuel4 ,by t "t ! g5ius (  
man w h devis$ an economical means (    
/or+ ! en]gy ( ! sunbeams directly =    
purposes ( heat1 light1 & p[]4          

,,*apt] ,,iv4  ,,slate ,,& ,,%ale4      
,slate is "o ( ! great comm]cial        
products ( ! _w4 ,z f> back z ! ye>     
#ahgg ! output ( slate 0 n less ?an     
#a1jjj1jjj tons p] annum4 ,! *ief use to
 :i* slate is put is = cov]+ build+s1 & 
= ?is purpose x is bett] ?an any o!r    
kn[n mat]ial4 ,x is also us$ 9 !        
con/ruction ( billi>d tables & =        
writ+-slates2 ^! latt] uses are v       
insignificant z comp>$ to its use 9     
ar*itecture4 ,slate1 l build+-/one &    
lime/one1 is qu>ri$ f ! e>?'s cru/ & is 
f\nd 9 ! /rata close above !            
,metamorphic rocks1 ne> ! beg9n+ ( :at  
is call$ ! ,prim>y1 or ,paleozoic p]iod4
 ,z comp>$ ) ! coal =mations x is v1 v  
old4  ,!re are diff]5t sub/ances call$  
slate t are n slate 9 ! sci5tific use ( 
t ^w4 ,9 g5]al all /one =mations are    
call$ slates t split up into ?9 lay]s4  
,b ! true slate is a special mat]ial :i*
 is =m$ by special processes ( nature4  
,! diff]5ce betwe5 slate & %ale1 =      
in/ance1 is n "o ( +r$i5ts1 b ( !       

process by :i* ! +r$i5ts are put toge!r4
 ,all ( ! s$im5t>y rocks are =m$ by a   
deposit ( s$im5t f ! wat] on ! bottom ( 
! ocean4 ,at "o p]iod ! floods h br\ght 
d[n a c]ta9 k9d ( mat]ial 9 great]      
pr(usion ?an at o!rs1 & ?is is deposit$ 
9 ?9 lay]s1 & z x h>d5s !re w be seams 9
 x & ! /ratifications w be diff]5tly    
color$1 ! color dep5d+ ^u ! deposit at  
any p>ticul> "t4  ,a b$ ( %ale1 l a b$ (
 coal1 has l9es ( cleavage 9 x1 & if x  
is exam9$ "u a microscope x w be f\nd t 
! s$im5t>y p>ticles1 l ! twigs & leaves 
9 ! coal ve9s1 lie ) _! longe/ dim5sions
 9 l9e ) ! plane ( cleavage4 ,%ale 9    
color looks l slate1 & an analysis ( !  
mat]ial ( :i* x is =m$ %[s t %ale &     
slate are bo? made f ! same4 ,!re is1   
h[ev]1 a /ructural diff]5ce betwe5 ! two
 :i* is v peculi> & v int]e/+4 ,! slate 
is ord9>ily a d5s] mat]ial & ! l9es (   
cleavage are (t5 at "r angles ) ^? t we 
f9d 9 ord9>y %ale4  ,a slab ( %ale w be 
( a uni=m color on any "o l9e (         
cleavage4 ,! color may *ange at ! next  

l9e1 & g5]ally does1 to a slight ext5t4 
,x is easy to see1 !n1 if we c\ld *ange 
! l9es ( cleavage 9 ! %ale1 s z to run  
at "r angles ) _! pres5t l9es1 ! face ( 
a slab w\ld %[ b&s ( diff]5t colors or  
%ad+s1 su* z we (t5 see 9 slate4 ,if y  
take a piece ( clay t has be5 ?or\ghly  
mix$1 & subject x to a v great pressure1
 & !n exam9e ! piece t has be5 submitt$ 
to pressure "u a microscope & comp>e x )
 a piece ( ! clay aft] x has be5        
?or\ghly mix$1 b has n be5 submitt$ to  
pressure1 y w f9d t ! two are v diff]5t 
9 /ructure4 ,! press$ clay w %[ t !     
p>ticles ( :i* x is made up h all turn$1
 s t _! longe/ dim5sions are 9 a l9e at 
"r angles ) ! direction ( pressure4 ,"h 
is an int]e/+ fact t we mu/ rememb]4 ,& 
x is 9 ?is t we f9d ! reason = !        
/ructural diff]5ce betwe5 %ale & slate4 
,! l9es ( cleavage 9 %ale are n =m$     
necess>ily by pressure1 b because 9 !   
disposition ( ! mat]ial ( :i* x 0 =m$ ! 
p>ticles naturally laid !mselves d[n s t
 _! longe/ dim5sions 7 on a horizontal  

l9e4  ,ages aft]1 :5 o!r rock & o!r     
=mations _h be5 laid d[n on top ( ! b$ (
 deposit$ mud1 ! upheavals ( ! e>? h s  
*ang$ ! l9es ( pressure ^u ?is mat]ial &
 ! pressure is s great t a re>rangem5t (
 ! p>ticles ( :i* ! slate is made up has
 tak5 place1 s t _! longe/ dim5sions n[ 
are 9 a direction t crosses !           
/ratifications z orig9ally laid d[n4  ,!
 effect ( ?is is tw(old4 ,fir/1 !       
mat]ial is compress$ into a d5s]1 clos] 
=m1 & !n1 ! l9es ( cleavage are *ang$1  
or to express x 9 m common language1 !  
gra9 has be5 *ang$4 ,s t :5 x splits up 
x runs crosswise ( ! orig9al lay]s z !  
wat] deposit$ !m1 & ?is produces !      
diff]5t %ad+s s (t5 se5 9 diff]5t slate4
 ,%ale splits 9 l9e ) its lay]s2 slate  
splits across t l9e4  ,let u g back a   
mom5t to our exp]im5t ) ! lump ( clay4  
,if we exam9$ ! mixture be=e submitt$ to
 pressure we %\ld f9d t ! oblong        
p>ticles ( :i* x 0 made up w\ld /& 9 all
 directions1 hit or miss1 & if we %\ld  
dry ?is lump ( clay x w\ld h no special 

l9es ( cleavage4 ,b ! mom5t we h        
submitt$ x to a c]ta9 am\nt ( pressure  
we f9d t l9es ( cleavage h be5 e/abli%$1
 & t ! p>ticles h be5 re>rang$ s t _!   
longe/ dim5sions are all 9 "o direction1
 :i* co9cides ) ! cleavage l9es4 ,if we 
%\ld n[ take ?is same piece ( clay &    
subject x to a pressure at "r angles to 
t ( ! fir/ exp]im5t we %\ld f9d t ! l9es
 ( cleavage _h also *ang$ & t ! p>ticles
 _h all be5 re>rang$4 ,apply ! pr9ciple 
to ! =mation ( slate1 & we c und]/& h[ x
 happ5s t :at we call ! gra9 runs       
crosswise ( ! deposits t 7 made at      
diff]5t times4 ,x is n a *emical1 b     
purely a me*anical diff]5ce4 ,or1 to    
express x diff]5tly--! diff]5ce is a    
/ructural "o produc$ by me*anical       
causes4  ,! orig9 ( cleavage 9 slate has
 be5 ! subject ( mu* speculation &      
inve/igation1 b l _m o!r problems x 0   
solv$ ?r\gh ! inv5tion & application ( !
 microscope4 ,?9 lay]s ( slate h be5    
made1 ! same z ) lime/one & *alk1 s ?9 t
 ! light w\ld readily pass ?r\gh x & t  

an exam9ation ( ! p>ticles c\ld be      
readily made1 %[+ _! arrangem5t "u v>i$ 
conditions4 ,sci5ce is indebt$ to !     
microscope = ! solution ( v _m problems 
t = ages be=e _h puzzl$ philosoph]s4    
,,*apt] ,v4  ,,salt4   ,x may seem      
curi\s to ! read] t we %\ld c>e to      
discuss a subject seem+ly s simple z    
common salt4 ,b x is a v usual ?+ = u to
 live & move 9 ! pres5ce ( ?+s t are v  
common to our ev]yday exp]i5ce1 & yet "k
 sc>cely any?+ ab\t !m1 beyond ! fact t 
!y 9 "s way s]ve our purpose4  ,salt is 
"o ( ! commone/ articles us$ 9 !        
prep>ation ( our food4 ,x has be5       
que/ion$ by "s p :e!r salt 0 a real     
necessity z an animal food1 or :e!r !   
ta/e = x is m]ely an acquir$ "o4 ,all   
peoples 9 all ages seem to h us$ salt1 &
 ref]5ce to x is made 9 ! e>lie/        
hi/ories4 ,travel]s tell u t savage     
tribes1 :]ev] !y exi/1 are z mu* addict$
 to ! use ( salt z civiliz$ p4 ,"o ( !  
e>ly ,african travel]s1 ,mungo ,p>k1    
tells u t ! *ildr5 ( c5tral ,africa w   

suck a piece ( rock salt ) ! same       
avidity & seem+ satisfaction z ! ord9>y 
civiliz$ *ild w a lump ( sug>4  ,all    
animals seem to require salt1 & x is    
claim$ by ^? :o h tri$ ! exp]im5t t aft]
 "o has refra9$ f ! use ( salt = a c]ta9
 l5g? ( "t ! crav+ = x becomes exce$+ly 
pa9ful4 ,x is mo/ likely t ! ta/e = salt
 is a natural crav+4 ,9 any ev5t1 :e!r x
 is a natural or an artificial ta/e1 x  
has become an article ( ! greate/       
importance 9 ! prep>ation ( food1 z well
 z on acc\nt ( its use 9 ! arts4 ,salt  
is a comp\nd ( *lor9e & sodium4 ,9      
*emical language x is call$ sodium      
*loride4 ,! symbol is ,na,cl1 :i* means 
t a molecule ( salt is compos$ ( "o atom
 ( sodium & "o ( *lor9e4 ,*lor9e is an  
exce$+ly poison\s gas4  ,=m]ly ! *emi/  
:5 he wi%$ to obta9 sodium extract$ x f 
common salt & dis*>g$ ! *lor9e gas into 
! air4 ,x 0 f\nd t 9 e/abli%m5ts :]e !  
manufacture ( sodium 0 conduct$ on a    
l>ge scale ! de/ructive prop]ties ( !   
*lor9e dis*>g$ into ! air 0 su* t all   

vegetation 0 kill$ = "s di/ance ar\nd ! 
manufactory4 ,?is came to be su* a      
nuisance t ! manufactur]s 7 ei!r        
compell$ to /op bus9ess or 9 "s way take
 c>e ( ! *lor9e4 ,?is is done at !      
pres5t day by unit+ ! *lor9e gas )      
common lime1 =m+ a *loride ( lime1 :i*  
is us$ = blea*+ & purify+ purposes4     
,salt is f\nd 9 great quantities z a    
natural product "u ! "n ( rock salt4 ,x 
is f\nd 9 "s p>ts ( ! _w 9 great ve9s   
ov] #ajj feet 9 ?ickness4 ,9 "s cases ! 
rock salt is m9$1 :5 x has to be purifi$
 = comm]cial purposes4 ,! common mode ( 
obta9+ salt1 h[ev]1 is by pump+ !       
solution f ^! great b$s :]e x is m+l$ ) 
wat]--salt wat]2 ! wat] is !n evaporat$1
 & :5 x rea*es a c]ta9 /age (           
evaporation ! salt cry/allizes & falls  
to ! bottom4  ,diff]5t sub/ances        
cry/allize 9 diff]5t =ms4 ,!            
cry/allization ( wat] :5 x freezes1 z we
 %all see h]eaft]1 arranges its         
molecules 9 su* a =m z to make a lump ( 
ice ( giv5 dim5sions light] ?an ! same  

dim5sions ( wat] w\ld be4 ,salt 9       
cry/alliz+ does n foll[ ! same law2 !   
salt cry/al is 9 ! %ape ( a cube & is   
d5s] 9 its cry/all9e =m ?an 9 solution1 
h5ce x is heavi] & falls to ! bottom4   
,x is said t !re is a deposit ( rock    
salt 9 ,galicia1 ,au/ria1 cov]+ an area 
( #aj1jjj squ>e miles4 ,!re are also v  
l>ge deposits 9 ,engl&1 ! m9+ ( :i* has 
become a great indu/ry4 ,!re are also   
great b$s ( salt 9 v>i\s p>ts ( ! ,unit$
 ,/ates1 notably ne> ,syracuse1 ,n4 ,y41
 :]e l>ge salt deposits 7 expos$ 9 an   
old riv] b$ =m$ 9 preglacial times4 ,!  
common mode ( prep>+ salt = dome/ic     
purposes is by ! process ( evaporation f
 br9e t has be5 pump$ f salt wells4 ,!  
quality ( ! salt is det]m9$ l>gely by ! 
temp]ature at ! "t ( evaporat+ ! wat] f 
x4 ,ord9>y co>se salt1 su* z is us$ =   
pres]v+ meat or fi%1 is made at a       
temp]ature ( ab\t #aaj degrees2 :at is  
kn[n z common salt is made at a         
temp]ature ( ab\t #age degrees2 :ile    
common f9e or table salt is made at a   

temp]ature ( #bbj degrees4 ,?us x w be  
se5 t ! process ( granulation ) ref]5ce 
to its f95ess is det]m9$ by ! rapidity (
 evaporation4 ,salt is "o ( ! pr9cipal  
ag5ts 9 pres]v+ all k9ds ( meats aga9/  
putrefaction4 ,x w also pres]ve wood    
aga9/ dry rot4 ,vessel build]s make use 
( ?is fact to pres]ve ! timb]s us$ 9 !  
con/ruction ( ! vessels4  ,salt at !    
pres5t day is v *eap1 b at ! beg9n+ ( ! 
pres5t c5tury x 0 wor? f #fj to #gj p]  
ton4 ,! me?ods ( decompos+ salt to obta9
 its con/itu5ts1 :i* are us$ 9 v>i\s o!r
 comp\nds1 are v simple to-day z comp>$ 
) ! processes t prevail$ 9 ! days be=e !
 adv5t ( electricity 9 l>ge volume1 su* 
z is produc$ by ! p[] ( ,niag>a ,falls4 
,x is curi\s to note t a sub/ance s     
useful & s h>mless z common salt %\ld be
 made out ( two su* refractory & dang]\s
 elem5ts z *lor9e & sodium4 ,bo? ( ^!   
elem5ts1 /&+ by !mselves1 seem to be out
 ( h>mony ) nature1 b :5 comb9$ !re are 
few sub/ances t s]ve a bett] purpose4   
,^! great salt b$s t are f\nd to exi/ 9 

,engl& & ,am]ica & o!r p>ts ( ! _w 7    
und\bt$ly deposit$ f ! wat] ( ! ocean at
 "s /age 9 ! =mation ( ! e>?'s cru/4 ,x 
is well kn[n t sea wat] is exce$+ly     
sal9e2 #cjj gallons ( sea wat] w produce
 a bu%el ( salt4 ,und\bt$ly b$s ( salt  
are also =m$ by inl& lakes1 su* z !     
,great ,salt ,lake 9 ,utah4 ,only ab\t  
#b4g p] c5t4 ( ocean wat] is salt1 :ile 
! wat] ( ! ,great ,salt ,lake ( ,utah   
conta9s ab\t #ag p] c5t4 ,:5 !re is s   
mu* salt 9 wat] t x is call$ a saturat$ 
solution1 salt cry/als w =m & drop to ! 
bottom1 :i* process w 9 "t build up "u a
 l>ge body ( salt wat] a great b$ ( rock
 salt4  ,! wat] 9 all riv]s & spr+s     
conta9s salt to a c]ta9 degree1 & :]e x 
runs into a bas9 l t ( a lake ) no      
outlet1 ?r\gh ! process ( evaporation   
pure wat] is be+ con/antly c>ri$ (f1    
leav+ ! salt beh9d4 ,x is easy to see t 
if ?is process is kept up long en\gh !  
wat] w become 9 "t a saturat$ solution1 
:5 cry/allization sets 9 & precipitation
 foll[s1 acc\nt+ = ! deposits ( rock    

salt4     ,,air4     ,,*apt] ,,vi4  ,,! 
,,atmosph]e4   ,meteorology is a sci5ce 
t at "o "t includ$ a/ronomy1 b n[ x is  
re/rict$ to ! wea!r1 seasons1 & all     
ph5om5a t are manife/$ 9 ! atmosph]e 9  
its relation to heat1 electricity1 &    
moi/ure1 z well z ! laws t gov]n !      
ev]-v>y+ conditions ( ! circumambi5t air
 ( our globe4 ,! air is made up *iefly (
 oxyg5 & nitrog51 9 ! proportions ( ab\t
 tw5ty-"o p>ts ( oxyg5 & sev5ty-n9e p>ts
 nitrog5 by volume1 & by weight ab\t    
tw5ty-?ree p>ts oxyg5 & sev5ty-sev5 (   
nitrog54 ,^! gases exi/ 9 ! air z free  
gases & n *emically comb9$4 ,! air is   
simply a mixture ( ^! two gases4  ,!re  
is a diff]5ce betwe5 a mixture & a      
comp\nd4 ,9 a mixture !re is no *emical 
*ange 9 ! molecules ( ! sub/ances mix$4 
,9 a comp\nd !re has be5 a re>rangem5t (
 ! atoms1 new molecules are =m$1 & a new
 sub/ance is ! result4  ,ab\t #ii-a_/b  
p] c5t4 ( air is oxyg5 & nitrog5 &      
"o-half p] c5t4 is *iefly c>bon dioxide4
 ,c>bon dioxide is a product (          

combu/ion1 decay1 & animal exhalation4  
,x is poison to ! animal1 b food = !    
vegetable4 ,h[ev]1 ! proportion 9 ! air 
is s small t its baneful influ5ce ^u    
animal life is r$uc$ to a m9imum4 ,!    
nitrog5 is an in]t1 odorless gas1 & its 
use 9 ! air seems to be to dilute x1 s t
 man & animals c brea! x4 ,if all !     
nitrog5 7 extract$ f ! air & only !     
oxyg5 left to brea!1 all animal life    
w\ld be /imulat$ to dea? 9 a %ort "t4 ,!
 pres5ce ( ! nitrog5 prev5ts too mu*    
oxyg5 f be+ tak5 into ! sy/em at once4  
,i suppose m5 & animals might h be5 s   
organiz$ t !y c\ld brea! pure oxyg5 )\t 
be+ hurt1 b !y 7 n1 = "s reason1 made t 
way4  ,air conta9s m or less moi/ure 9 !
 =m ( vapor2 ?is subject1 h[ev]1 w be   
discuss$ m fully "u ! head (            
evaporation4 ,! air at sea-level weighs 
fifte5 p\nds to ! squ>e in*1 & if ! :ole
 envelope ( air 7 homog5e\s--! same 9   
"*--x w\ld rea* only ab\t five miles    
high4 ,b z x becomes gradually r>efi$ z 
we asc5d1 x probably ext5ds 9 a v ?9    

/ate to a height ( eighty or n9ety      
miles2 at lea/1 at t height we %\ld f9d 
a m p]fect vacuum ?an c be produc$ by   
artificial means4 ,! weight ( all ! air 
on ! globe w\ld be #aa-b_/c trillion    
p\nds if no d$uction _h to be made =    
space fill$ by m\nta9s & l& above       
sea-level4 ,z x is1 ! :ole bulk weighs  
some?+ less ?an ! above figures4  ,z we 
h said1 ! air envelopes ! globe to a    
height at sea-level ( eighty or n9ety   
miles1 gradually ?9n+ out into ! e!r t  
fills all int]/ell> space4 ,we live &   
move on ! bottom ( a great ocean ( air4 
,! birds fly 9 x j z ! fi% swim 9 !     
ocean ( wat]4 ,bo? are transp>5t & bo? h
 weight4 ,wat] 9 ! cond5s$ /ate is      
heavi] ?an ! air & w seek ! l[e/ places1
 b :5 vaporiz$1 z 9 ! process (         
evaporation1 x is light] ?an air &      
floats upw>d4 ,9 ! vapor /ate x is      
transp>5t l /eam4 ,if y /udy a /eam jet 
y w notice t = a %ort di/ance aft] x    
issues f ! boil] x is transp>5t1 b soon 
x cond5ses into cl\d4  ,if we c\ld see  

inside ( a boil] 9 :i* /eam _h be5      
g5]at$1 all ! space n occupi$ ) wat]    
w\ld seem to be vacant1 s9ce /eam be=e x
 is cond5s$ is z transp>5t z ! air4 ,we 
w1 h[ev]1 speak ( ?is subject m fully "u
 ! head ( evaporation & cl\d =mation4 ,x
 is n en\gh t we h ! air 9 :i* we live &
 move1 ) all ( its prop]ties1 z we h    
describ$3 some?+ m is ne$$ :i* is       
absolutely ess5tial bo? to animal &     
vegetable life--& ?is ess5tial is       
motion4 ,if ! air rema9$ p]fectly /ill )
 no lat]al movem5t or upw>d & d[nw>d    
curr5ts ( any k9d1 we %\ld h a p]fectly 
con/ant condition ( ?+s subject$ only to
 su* gradual *anges z ! advanc+ & rec$+ 
seasons w\ld produce ow+ to ! *ange 9 ! 
angle ( ! sun's rays4 ,no cl\d w\ld ev] 
=m1 no ra9 w\ld ev] fall1 & no w9d w\ld 
ev] bl[4 ,x is ( ! highe/ importance n  
only t ! w9d %all bl[1 b t comp>atively 
sudd5 *anges ( temp]ature take place 9 !
 atmosph]e1 9 ord] t vegetation z well z
 animal life may exi/ ^u ! surface ( !  
globe4 ,! only place :]e animal life    

c\ld exi/ w\ld be 9 ! great bodies (    
wat]1 & x is ev5 d\btful if wat] c\ld   
rema9 habitable unless !re 7 means      
provid$ = con/ant circulation--motion4  
,! mobility ( ! atmosph]e is su* t !    
lea/ influ5ce t *anges its balance w put
 x 9 motion4 ,:ile we c acc\nt 9 a g5]al
 way = atmosph]ic movem5ts1 !re are _m  
problems relat+ to ! details t are      
unsolv$4 ,we f9d t ev5 ! wea!r man makes
 mi/akes 9 8 progno/ications2 s true is 
?is t x is nev] safe to plan a picnic = 
to-morr[ bas$ ^u ! pr$ictions ( to-day4 
,! *ief difficulty 9 ! way ( solv+ !    
great problems relat+ to ! sudd5 *anges 
9 ! wea!r & temp]ature lies 9 ! fact t  
two-?irds or m ( ! e>?'s surface is     
cov]$ ) wat]2 ?us mak+ x impossible to  
e/abli% /ations = obs]vation t w\ld be  
ev5ly di/ribut$ all ov] ! e>?'s surface4
 ,en\gh is kn[n1 h[ev]1 to make ! /udy (
 meteorology a mo/ wond]fully int]e/+   
subject4  ,we h already /at$ t air is   
compos$ ( a mixture ( oxyg5 & nitrog5   
*iefly1 ) a small am\nt ( c>bon dioxide4

 ,s f> z ! life & heal? ( ! animal is   
conc]n$ we c\ld get along )\t ?is latt] 
sub/ance1 b x seems to be a necessity 9 
! gr[? ( vegetation4 ,!re are o!r ?+s 9 
! air :i*1 :ile !y are unnecess>y =     
brea?+ purposes1 x w be well = u to     
und]/&1 z "s ( !m are ?+s to be avoid$ r
 ?an inhal$4  ,z be=e m5tion$1 air      
conta9s moi/ure1 :i* is a v v>iable     
quantity4 ,9 a cold day 9 w9t] x is n m 
?an "o-?\s&? "p1 :ile 9 a w>m day 9     
summ] x may equal "o-=tie? ( ! quantity 
( air 9 a giv5 space4 ,!re is also a    
small am\nt ( ammonia1 p]haps n ov]     
"o-sixty-million?4 ,oxyg5 also exi/s 9 !
 air 9 v small quantities 9 ano!r =m    
call$ ozone4 ,"o way to produce ozone is
 by pass+ an electric sp>k ?r\gh air4   
,anyone :o has op]at$ a ,holtz ma*9e has
 notic$ a peculi> smell att5d+ !        
disruptive dis*>ges1 :i* is ! odor (    
ozone4 ,x is :at *emi/s call an         
allotropic =m ( oxyg51 j z ! diamond1   
graphite1 & *>coal are all diff]5t =ms (
 c>bon1 & yet ! *emical diff]5ces are   

sc>cely traceable4 ,x is m /imulat+ to  
brea! ?an oxyg5 & is probably produc$ by
 lightn+ dis*>ges4  ,z has be5 be=e     
/at$1 ! oxyg5 ( ! air is consum$ by all 
processes ( combu/ion1 & 9 ?is we       
include ! brea?+ ( m5 & animals & !     
decay ( vegetable matt]1 z well z ! m   
active combu/ion aris+ f fires4 ,a gr[n 
p]son consumes some?+ ov] #djj gallons (
 oxyg5 p] day1 & x is e/imat$ t all !   
fires on ! e>? consume 9 a c5tury z mu* 
oxyg5 z is conta9$ 9 ! air ov] an area (
 sev5ty miles squ>e4 ,all ( ^! processes
 are ?r[+ into ! air c>bon dioxide      
7c>bonic acid71 :i*1 h[ev]1 is (fset by 
! p[] ( vegetation to absorb x1 :]e !   
c>bon is reta9$ & =ms a "p ( ! woody    
fib] & pure oxyg5 is giv5 back into !   
air4 ,by ?is process ! normal conditions
 ( ! air are ma9ta9$4  ,"o decimet]     
7ne>ly #d in*es7 squ>e ( gre5 leaves w  
decompose 9 "o h\r sev5 cubic c5timet]s 
( c>bon dioxide1 if ! sun is %9+ on !m2 
9 ! %ade ! same area w absorb ab\t ?ree 
9 ! same "t4  ,!re is ano!r sub/ance 9 !

 =m ( vegetable g]ms 9 ! air call$      
bact]ia4 ,at "o "t ^! 7 suppos$ to be l[
 =ms ( animal life1 b x is n[ det]m9$ t 
!y are ! l[e/ =ms ( vegetable g]ms4     
,bact]ia is ! g5]al or g5]ic "n = a l>ge
 class ( g]ms1 _m ( !m disease g]ms4 ,by
 analysis ( ! air 9 diff]5t locations & 
9 diff]5t p>ts ( ! c\ntry x has be5     
det]m9$ t on ! ocean & on ! m\nta9 tops 
^! g]ms av]age only "o to ea* cubic y>d 
( air4 ,9 ! /reets ( ! av]age city !re  
are #cjjj ( !m to ! cubic y>d1 :ile 9   
o!r places :]e !re is sickness1 z 9 a   
hospital w>d1 !re may be z _m z #hj1jjj 
to ! cubic y>d4 ,^! facts g to prove :at
 has long be5 well kn[n1 t ! air ( a    
city furni%es _m m fruitful s\rces =    
disease ?an t ( ! c\ntry4 ,"s =ms (     
bact]ial g]ms are n consid]$ h>mful1 &  
!y probably p]=m ev5 a useful s]vice 9 !
 economy ( nature4 ,)9 c]ta9 limits1 o!r
 ?+s be+ equal1 ! high] "o's dwell+ is  
locat$ above ! common level ! pur] w be 
! air4 ,?is rule1 h[ev]1 has its limits1
 z ! oxyg5 ( ! air is heavi] ?an !      

nitrog51 s t ! air at v great altitudes 
has n ! same proportion ( oxyg5 to      
nitrog5 t x has at a l[] level4 ,an     
analysis t 0 made "s ye>s ago ( ! air on
 ! we/ %ore ( ,lake ,mi*igan1 especially
 t section :]e ! bluffs are high1 %[s t 
x comp>es favorably ) t ( any o!r       
portion ( ! ,unit$ ,/ates4  ,9 view ( ! 
=ego+1 x is ( ! highe/ importance to !  
sanit>y condition ( any city1 t[n1 or   
village t x be n too compactly built4   
,if m ?an a c]ta9 numb] ( p occupy a    
giv5 area1 x is absolutely impossible to
 pres]ve p]fect sanit>y conditions4 ,&  
!re ought to be a ,/ate law1 especially 
= all suburban t[ns1 :i* are ! homes &  
sleep+ places = l>ge numb]s ( bus9ess m5
 :o sp5d _! days 9 ! f\l air ( ! city1  
/ipulat+ t ! h\ses %all be n less ?an a 
c]ta9 di/ance ap>t4 ,oxyg5 is ! great   
purifi] ( ! blood1 & if "o does n get   
en\gh ( x he suff]s ev5 ?\gh he brea!s  
no impurities4 ,! p[] to resi/ ! effects
 ( bad air is mu* great] :5 "o is awake 
& active ?an :5 asleep1 & ?is is :y x is

 m important to sleep 9 pure air ?an to 
be 9 x dur+ our wak+ h\rs4 ,x is be/1   
h[ev]1 to be 9 good air all ( ! "t4 ,by 
pure air ,i d n mean pure oxyg51 b ! "r 
mixture ( ! two gases t make air4 ,too  
mu* ( a good ?+ is (t5 worse ?an n      
en\gh4 ,pure food to eat1 pure wat] to  
dr9k1 & pure air to brea! w\ld soon be !
 f9ancial ru9 ( a l>ge class ( doctors4 
,,*apt] ,,vii4  ,,air ,,temp]ature4   ,!
 mo/ rec5t def9ition ( heat is t x is a 
mode ( motion2 n movem5t ( a mass (     
sub/ance1 b movem5t ( its ultimate      
p>ticles4 ,x has be5 det]m9$ by exp]im5t
 t ! ability ( any sub/ance to absorb   
heat dep5ds ^u ! numb] ( atoms x        
conta9s1 r ?an its bulk or its weight4  
,x has also be5 /at$ t ! atmosph]e at   
sea-level weighs ab\t fifte5 p\nds to ! 
squ>e in*1 :i* means t a column ( air "o
 in* squ>e ext5d+ f sea-level upw>d to !
 extreme limit ( ! atmosph]e weighs     
fifte5 p\nds4 ,! d5sity ( ! air         
decreases z we asc5d4 ,ea* successive   
lay]1 z we asc5d1 is m & m exp&$1 &     

consequ5tly has a less & less numb] (   
air molecules 9 a giv5 space4 ,!re=e !  
capacity ( ! air = hold+ heat decreases 
z we g high]4  ,we d$uce f ^! facts t ! 
high] we g ! cold] x becomes2 & ?is we  
f9d to be ! case4 ,:oev] has asc5d$ a   
high m\nta9 has _h no difficulty 9      
det]m9+ two ?+s4 ,"o is t ! air is v mu*
 cold] ?an at sea-level1 & ! o!r t x is 
v mu* light] 9 weight4 ,we f9d x        
difficult1 :5 we fir/ rea* ! summit1 to 
take en\gh ( oxyg5 into our lungs to    
c>ry on ! natural op]ations ( ! bodily  
functions4 ,to ov]come ?is difficulty1  
if we rema9 at ?is altitude = a         
consid]able "t1 we %all f9d t our lungs 
h exp&$1 s z to make up 9 quantity :at  
is lack+ 9 quality4  ,if a man lives = a
 long "t at an altitude ( #aj1jjj feet  
he w f9d t 8 lungs are s exp&$ t he     
exp]i5ces "s difficulty :5 he comes d[n 
to sea-level4 ,& ! rev]se is true ) "o  
^: lungs are adapt$ to ! conditions we  
f9d at sea-level1 :5 he asc5ds to a     
high] altitude4 ,!re is a con/ant       

endeavor on ! "p ( nature to adapt bo?  
animal & vegetable life to ! surr\nd+s4 
,:ile no exact =mula has be5 e/abli%$ z 
to ! rate ( decrem5t ( temp]ature z we  
asc5d1 we may say t x decreases ab\t "o 
degree 9 e #cjj or #djj feet ( asc5t4   
,!re is no exact way ( arriv+ at ?is1 z 
9 asc5d+ a m\nta9 ! temp]ature w be m or
 less affect$ by local conditions4 ,if  
we g up 9 a balloon we h to dep5d ^u !  
b>omet] z a means ( measur+ altitude1   
:i*1 ow+ to ! v>y+ atmosph]ic           
conditions1 is n a reliable mode (      
measurem5t4 ,x is easily und]/ood t a   
cubic foot ( air at sea-level w conta9 a
 great _m m atoms ?an a cubic foot ( air
 w at ! top ( a high m\nta92 or1 to /ate
 x 9 ano!r way1 a cubic foot ( air at   
sea-level w occupy mu* m ?an a cubic    
foot ( space #aj1jjj feet high] up4     
,suppose1 !n1 t ! am\nt ( heat held 9 a 
cubic foot ( air at sea-level rema9$ !  
same1 z relat$ to ! numb] ( atoms4 ,9   
its asc5t we %all f9d t at a high       
altitude ! same numb] ( atoms t 7 held  

at sea-level 9 a cubic foot h be5       
di/ribut$ ov] a s mu* l>g] space t !    
s5sible heat is greatly dim9i%$ or      
dilut$1 s to speak4 ,x 0 an old notion t
 heat w\ld hide itself away 9 fluids "u 
a "n call$ by sci5ti/s lat5t heat4 ,?is 
!ory has be5 explod$1 h[ev]1 by mod]n   
inve/igation4  ,if we place "s sub/ance 
t w inflame at a l[ temp]ature 9 !      
bottom ( :at is call$ a fire syr+e 7:i* 
is no?+ b a cyl9d] bor$ out smoo?ly1 ) a
 pi/on head nicely fitt$ to x1 s t x w  
be air-tight7 & !n sudd5ly cond5se ! air
 9 ! syr+e by %ov+ ! plung] to ! bottom1
 we c inflame ! sub/ance :i* has be5    
plac$ 9 ! bottom ( ! cyl9d]4 ,9 ?is     
op]ation ! heat t 0 di/ribut$ ?r\gh !   
:ole body ( air1 t 0 conta9$ 9 ! cyl9d] 
be=e x 0 compress$1 is n[ cond5s$ into a
 small space4 ,if we )draw ! plung]     
imm$iately1 be=e ! heat has be5 tak5 up 
by ! walls ( ! syr+e1 we %all f9d ! air 
( ! same temp]ature z be=e ! plung] 0   
?ru/ d[n4 ,?is1 h[ev]1 does n take into 
acc\nt any heat t 0 g5]at$ by friction4 

,let u fur!r illu/rate ! ph5om5on by    
ano!r exp]im5t4 ,if we sudd5ly compress 
a cubic foot ( air at ord9>y pressure   
into a cubic in* ( space1 t cubic in* w 
be v hot because x conta9s all ! heat t 
0 di/ribut$ ?r\gh ! entire cubic foot   
be=e ! compression took place4 ,n[ let x
 rema9 compress$ until ! heat has       
radiat$ f x1 z x soon w1 & ! air becomes
 ( ! same temp]ature z ! surr\nd+ air4  
,:at ought to happ5 if !n we %\ld       
sudd5ly all[ ?is cubic in* ( air to exp&
 to its normal pressure1 :5 x w occupy a
 cubic foot ( space8  ,inasmu* z we     
all[$ ! heat to escape f x :5 9 !       
cond5s$ =m1 :5 x exp&s x w be v cold1   
because ! heat ( ! cubic in*1 n[ r$uc$  
to ! normal temp]ature ( ! surr\nd+ air1
 is di/ribut$ ov] a cubic foot ( space4 
,?is is precisely :at takes place :5    
heat$ air at ! surface ( ! e>? 7:i* is  
cond5s$ to a c]ta9 ext5t7 rises to !    
high] regions ( ! atmosph]e4 ,!re is a  
gradual expansion z x asc5ds1 &         
consequ5tly a gradual cool+1 because a  

giv5 am\nt ( heat is be+ con/antly      
di/ribut$ ov] a great] am\nt ( space4   
,at an altitude ( =ty-five miles x w h  
exp&$ ab\t #be1jjj times1 :i* w br+ !   
temp]ature d[n to betwe5 #bjj & #cjj    
degrees bel[ z]o4  ,:5 we get beyond !  
limits ( ! atmosph]e we get into !      
region ( absolute cold1 because heat is 
atomic motion1 & !re c be no atomic     
motion :]e !re are no atoms4  ,we h n[  
trac$ ! atmosph]e up to ! po9t :]e x    
%ades (f into ! e!r t is suppos$ to fill
 all int]planet>y space4 ,z ,dryd5 says3
      ,!re fields ( light & liquid e!r  
fl[1     ,purg'd f ! pond'r\s dregs (   
e>? bel[4  ,by int]planet>y space we    
mean all space betwe5 ! planets n       
occupi$ by s5sible mat]ial4 ,x is ! same
 z int]atomic space1 or ! space betwe5  
atoms1 except 9 degree1 z ! same        
sub/ance t fills int]planet>y space also
 fills int]atomic space1 s t all ! atoms
 ( matt] float 9 x & are held toge!r f  
fly+ (f into space by ! attraction (    
cohesion4 ,:at ?is e!r is1 has be5 !    

subject ( mu* speculation among         
philosoph]s1 )\t1 h[ev]1 arriv+ at any  
def9ite conclusion1 fur!r ?an t x is a  
sub/ance possess+ almo/ inf9ite         
ela/icity1 & ^: ultimate p>ticles1 if   
p>ticles !re be1 are s small t no       
s5sible sub/ance c be made suffici5tly  
d5se to resi/ x or conf9e x4 ,x is easy 
to see t a sub/ance possess+ su*        
qualities _c be weigh$ or 9 any way made
 appreciable to our s5ses4 ,b f ! fact t
 radiant en]gy c be transmitt$ ?r\gh x1 
) vibrations am\nt+ to billions p]      
second1 we "k t x mu/ be a sub/ance )   
ela/ic qualities t approa* ! inf9ite4   
,assum+ t ! e!r is a sub/ance1 ! "q     
arises h[ is x relat$ to o!r =ms (      
sub/ance8 ,?is is a "q m easily ask$ ?an
 answ]$4 ,! long] "o dwells ^u !        
subject1 h[ev]1 ! m "o is impress$ ) !  
?\ght t aft] all ! e!r may be ! "o      
elem5t out ( :i* all o!r elem5ts come4  
,*emi/ry tells u t !re are betwe5 sixty 
& sev5ty ultimate elem5ts4 ,?is is true 
at lea/ z a basis = *emical sci5ce4     

,*emical analysis has nev] be5 able to  
make gold any?+ b gold1 or oxyg5 any?+ b
 oxyg51 & s on ?r\gh ! :ole catalogue ( 
elem5ts4 ,x may be1 h[ev]1 t ! play (   
=ces "u & beyond ^? t seem to be active 
9 all *emical processes & relations1 are
 able to produce c]ta9 affections ( !   
e!r1 ! result ( :i* 9 ! "o case is an   
atom ( gold & 9 ! o!r an atom ( oxyg51  
etc41 to ! end ( ! li/4 ,9 ?is case all 
( ! s-call$ elem5ts may h _! orig9 9 "o 
fundam5tal elem5t t we call ! e!r4 ,i am
 aw>e t we are wad+ 9 deep wat] "h1 b   
sometimes we love to get into deep wat] 
j to try our swimm+ p[]s4 ,! above is a 
sugge/ion ( a !ory call$ ! vortex !ory1 
t is tak+ root 9 ! m9ds ( _m philosoph]s
 to-day1 & yet !re is almo/ no?+ ( kn[n 
facts to base su* a !ory ^u1 & ne>ly all
 we c say ab\t x is t x seems plausible1
 :5 view$ ?r\gh ! eye ( imag9ation4  ,we
 d "k t sub/ances1 su* z fluids or      
gases1 assume v diff]5t qualities :5 put
 into diff]5t rates ( motion4 ,a /raw   
has be5 kn[n to p5etrate ! body ( a tree

 endwise by ! extreme velocity imp>t$ to
 x :5 c>ri$ 9 ! vortex ( a tornado4     
,in/ances ( ! t]rific solid p[] (       
sub/ances t are mobile :5 at re/ are (t5
 exhibit$ dur+ ! progress ( a tornado1  
especially :5 conf9$ 9 v n>r[ limits4   
,sometimes a tornado cl\d w =m a hang+  
cone1 runn+ d[n to a %>p po9t at ! l[]  
end1 :i* l[] end may drag on ! gr\nd1 or
 x may float a little di/ance above !   
gr\nd1 b m frequ5tly x moves =w>d ) a   
b\nd+ motion1 n[ t\*+ ! e>? & n[ ris+ 9 
! air4 ,?is cone is revolv+ at a t]rific
 spe$4 ,! sub/ance revolv+ is *iefly    
air1 c>ry+ o!r light sub/ances t x has  
ga!r$ up f ! gr\nd4 ,if x comes 9       
contact ) a tree or build+ x cuts its   
way ?r\gh z ?\gh x 7 a buzzsaw revolv+  
at a high rate ( spe$4 ,?is is n simply 
! =ce ( w9d1 b a k9d ( solidity giv5 to 
! flu5t air by its :irl+ motion4  ,i    
rememb] a case 9 ,i[a1 :]e "o ( ^!      
revolv+ cones pass$ ?r\gh a b>ny>d1     
/rik+ ! corn] ( ! b>n1 cutt+ x (f z     
smoo?ly z ?\gh done ) "s %>p-edg$ tool1 

b x 9 no o!r way affect$ ! re/ ( !      
build+4 ,"o w\ld suppose t ! c5trifugal 
=ce develop$ 9 ?is :irl+ motion w\ld    
cause ! cone to fly ap>t1 & :y x does n 
no "o c]ta9ly kn[s4 ,b we are oblig$ to 
accept ! fact4  ,^! cases are cit$ to %[
 t motion gives rigidity to sub/ances t 
9 ! quiesc5t /ate are mobile or easily  
mov$1 l ! /raw or ! air4 ,if we %\ld    
assume t !re are inf9itesimal vortices  
or :irl+ r+s 9 ! e!r1 ( su* rapidity z  
to give x diff]5t degrees ( rigidity1 we
 c get a glimm]+ idea ( h[ an atom (    
matt] may be =m$ f e!r4  ,ref]r+ to !   
rigidity :i* motion gives to ord9>y     
matt]1 x is well kn[n t :5 two vessels  
at sea collide ! "o hav+ ! high] spe$ is
 n s liable to injury z ! "o ) ! l[]4 ,!
 read] w p]haps rememb] a circum/ance   
said to h occurr$ a few ye>s ago on !   
,lake ,%ore ,railroad1 betwe5 ,buffalo &
 ,clevel&4 ,! limit$ express 0 go+ we/1 
& :ile r\nd+ a curve ! eng9e] sudd5ly   
came 9 sight ( a wreck$ freight tra91 a 
"p ( :i* 0 ly+ on ! track :]e ! express 

tra9 _h to pass4 ,! eng9e] saw t he 0   
too ne> ! wreck to /op 8 tra9 & t ! only
 way to save 8 own tra9 & ! lives ( 8   
pass5g]s w\ld be to cut ?r\gh ! wreck4  
,he pull$ out ! ?rottle & put on a full 
head ( /eam1 & :5 ! tra9 /ruck ! wreck x
 0 go+ at su* a high rate ( spe$ t x cut
 ?r\gh )\t s]i\sly damag+ ! tra9 & )\t  
h>m to ! pass5g]s4  ,!re are o!r h]oes  
beside ^? :o lead armies 9 battle4      
,,*apt] ,,viii4                         
,,cl\d-,,=mation--,,evaporation4   ,wat]
 exi/s 9 diff]5t =ms )\t1 h[ev]1 und]go+
 any *emical *ange4 ,x is :5 cond5s$    
into ! fluid /ate t we call x wat]1 & !n
 x is heavi] ?an ! atmosph]ic air &     
!re=e seeks ! l[ places ^u ! e>?'s      
surface1 ! l[e/ ( :i* is ! b$ ( ! ocean4
 ,:]ev] !re is wat] or moi/ure on ! face
 ( ! globe !re is a process go+ on at ! 
surface call$ evaporation4 ,?is process 
is mu* m rapid "u ! action ( heat ?an :5
 x is cold]4 ,9 o!r words1 z ! heat     
increases evaporation increases )9 c]ta9
 limits & be>s "s sort ( a ratio to x4  

,evaporation is n conf9$ to wat]1 b z   
our subject has to deal ) atmosph]ic    
ph5om5a we w speak ( x only 9 its       
relation to aque\s moi/ure4  ,! heat t  
is imp>t$ to ! e>?'s surface by ! rays (
 ! sun is able to sep>ate wat] into     
m9ute p>ticles1 :i*1 :5 s sep>at$1 =m   
:at is call$ vapor1 :i* is transp>5t1 z 
well z mu* light] ?an ! air at ! surface
 ( ! e>?4 ,be+ light] ?an ! air1 x rises
 :5 dis5gag$ & floats to ! upp] regions 
( ! atmosph]e4 ,! atmosph]e w conta9 a  
c]ta9 am\nt ( ^! transp>5t globules (   
moi/ure 9 ! spaces betwe5 its own       
molecules4 ,if ! air is w>m ! molecules 
w be f>!r ap>t & x w conta9 m moi/ure   
?an :5 x is cold4  ,! process (         
evaporation is "o ( ! mo/ important 9 ! 
catalogue ( nature's dynamics4 ,)\t x   
!re w\ld be no v]dure on ! hills1 no    
trees on ! pla9s1 no fields ( wav+ gra91
 & no animal life ^u ! l& surface ( !   
globe4 ,evaporation is nature's me?od ( 
irrigation1 & ! sy/em is inaugurat$ on a
 gr& scale1 s t !re are b few neglect$  

spots ^u ! face ( ! e>? :i* moi/ure1    
c>ri$ up f ! great res]voirs ( wat]1    
does n rea*4 ,! rate ( evaporation1 o!r 
?+s be+ equal1 dep5ds ^u ! ext5t (      
surface2 !re=e a smoo? surface l t ( !  
lake or ocean w n s5d up z mu* vapor f a
 giv5 area 9 squ>e miles z an equal area
 ( l& w d1 :5 x is saturat$ ) moi/ure1 =
 ! reason t !re is a mu* l>g] evaporat+ 
surface on a squ>e mile ( l&1 ow+ to its
 inequalities1 ?an ^u an equal area (   
smoo? wat]4 ,( c\rse1 if ! e>? is dry   
!re c be b little evaporation4 ,"o ( !  
effects ( evaporation is to )draw heat1 
& s to produce cold 9 ! sub/ance f :i* !
 evaporation takes place4  ,if we put   
wat] into a vial & drop regul>ly ^u x "s
 fluid t evaporates readily x w extract 
! heat f ! vial & ! wat] 9 x to su* an  
ext5t t 9 a %ort "t ! wat] w be froz54  
,9 hot c\ntries ice is manufactur$ on a 
l>ge scale ^u ! pr9ciple t we h j       
describ$4 ,wat] is put into %all[ bas9s1
 excavat$ 9 ! e>?1 ov] :i* is plac$ "s  
sub/ance l /raw t readily radiates heat1

 & on ! /raw are plac$ por\s bricks1 t  
are kept wet1 ?us furni%+ a v l>ge      
evaporat+ surface4 ,9 ?is way ! process 
( evaporation is c>ri$ on v rapidly & ! 
heat is extract$ f ! wat] to su* an     
ext5t t x freezes1 (t5 =m+ ice 9 "o     
night ov] an in* 9 ?ickness1 & ?is 9 !  
hotte/ climates on ! globe4 ,evaporation
 _c g on 9 places :]e ! air is already  
saturat$ ) moi/ure4 ,:5 ! air is dry    
evaporation is v rapid1 b z x becomes m 
& m fill$ ) moi/ure ! evaporation is    
*eck$ to ! same degree4 ,?is fact       
acc\nts = ! diff]5ce ( bodily com=t t we
 exp]i5ce at diff]5t times 9 ! ye> :5 ! 
temp]ature is ! same4 ,sometimes we are 
v uncom=table al?\gh ! temp]ature is n  
above #ge degrees ,fahr5heit1 m s ev5   
?an we are at o!r times :5 ! temp]ature 
is t5 or fifte5 degrees high]4 ,if ! air
 is saturat$ ) moi/ure1 ev5 ?\gh !      
temp]ature is n above #gj or #ge        
degrees1 ! p]spiration is n readily     
evaporat$ f ! surface ( ! body4 ,if !   
air is dry ! temp]ature may be mu* high]

 & we be mu* m com=table1 because       
evaporation goes on rapidly1 :i* keeps !
 body n only dry1 b cool4 ,i rememb]    
pass+ ?r\gh a des]t 9 ,arizona :]e !re 0
 sc>cely a gre5 ?+ 9 sight 9 any        
direction1 & ! temp]ature 0 said to be  
#adj degrees4 ,i did n suff] z mu* z ,i 
(t5 h done 9 ! ,ea/ ) ! !rmomet] at #hj 
or #ij degrees1 & !re 0 v little %[ (   
s5sible p]spiration2 x 0 go+ on rapidly1
 h[ev]1 b 0 be+ absorb$ by ! dry air4   
,?is goes to %[ t temp]ature is n ! only
 factor to be consid]$ :5 we are mak+ an
 e/imate ( ! good or bad qualities ( a  
climate4  ,evaporation is c>ri$ on mu* m
 rapidly :5 ! w9d bl[s ?an at o!r times1
 = ! reason t ! moi/ure is c>ri$ (f     
lat]ally z fa/ z x is =m$1 all resi/ance
 to its escape into ! upp] air be+      
remov$4 ,if ! air is *>g$ to saturation 
) moi/ure at a c]ta9 temp]ature1 x w    
rema9 s1 & evaporation /ops s long z !  
temp]ature rema9s un*ang$4 ,if its      
temp]ature rises ! process ( evaporation
 c />t up1 because ! capacity ( ! air = 

hold+ moi/ure has be5 increas$4 ,b if a 
temp]ature is p]ceptibly l[]$ ano!r     
ph5om5on w manife/ itself4  ,9 !        
uncond5s$ /ate vaporiz$ moi/ure is q    
transp>5t1 s t we are able to see ?r\gh 
x z we d ?r\gh a pane ( glass4 ,if1     
h[ev]1 ! body ( air t is saturat$ ) ?is 
invisible moi/ure becomes sudd5ly *ill$1
 ! moi/ure cond5ses into cl\d or mi/4   
,if we wat* a pass+ railroad tra9 we    
%all notice a mass ( fleecy :ite mi/    
float+ away f ! smoke/ack1 assum+ !     
bill[y =ms ( "s ( ! cl\ds 9 summ]4 ,?is 
cl\d is produc$ by ! sudd5 cond5sation (
 /eam1 :i* 0 transp>5t be=e x came 9    
contact ) ! cold1 outside air1 ! effect 
be+ mu* m pron\nc$ 9 cold ?an 9 w>m     
wea!r4 ,we may lik5 ^! float+ globules (
 mi/ to ! du/ ( ! e>? :i* floats 9 !    
air1 & x has n be5 inaptly call$        
wat]-du/4 ,anyone :o has se5 an atomiz] 
us$ or has /ood at ! foot ( a great     
wat]fall1 l ,niag>a1 has se5 ! fluid s  
f9ely divid$ t x w float 9 ! air1 in/ead
 ( fall+ to ! gr\nd4 ,:at takes place is

 t a numb] ( ^! transp>5t atoms (       
moi/ure t are releas$ 9 ! process (     
evaporation coalesce into "o small drop 
or p>ticle ( wat]1 & !y w cont9ue to    
float 9 ! air z mi/ or cl\d until a     
suffici5t numb] h comb9$ into "o solid  
mass to r5d] t mass heavi] ?an ! air1 :5
 x falls 9 ! =m ( ra94  ,if we live 9 a 
region--& !re are su* on ! face ( !     
e>?--:]e !re is v little evaporation &  
consequ5tly v little moi/ure 9 ! air1   
!re is r>ely ev] a cl\d se5 nor is !re  
any ra9fall1 = ! reason t !re is no     
mat]ial exi/+ out ( :i* to =m cl\ds1 & !
 cl\ds prec$e ! ra94 ,h5ce1 all !       
artificial attempts to produce ra9 9 ^! 
arid regions h be5 futile4 ,if a body ( 
w>m air1 :5 saturat$ ) invisible        
moi/ure1 is sudd5ly *ill$ by com+ 9     
contact ) a cold wave1 x is squeez$ l a 
sponge1 s to speak1 & ! invisible       
p>ticles become visible because a numb] 
( !m h coalesc$ z "o p>ticle2 ! p>ticles
 ga!r 9 a l>ge mass1 & we h ! ph5om5on (
 cl\d =mation4  ,cl\ds m g5]ally =m 9 ! 

upp] regions ( ! atmosph]e because x is 
normally cold] 9 ! high] regions4 ,9 "s 
cases cl\ds float v high 9 ! air & 9    
o!rs v l[4 ,?is is due to two causes3   
,if we %\ld s5d up a balloon conta9+ air
 r>efi$ to a c]ta9 ext5t x w\ld cont9ue 
to asc5d only until x rea*$ a po9t :]e !
 outside air & t conta9$ 9 ! balloon are
 ( ! same d5sity4 ,if we %\ld s5d up ?is
 same balloon on diff]5t days ) ! same  
r>efaction ( int]nal air we %\ld f9d t  
on "s days x w\ld float high] ?an o!rs1 
because ! d5sity ( ! air is con/antly   
fluctuat+1 z is indicat$ by ! rise &    
fall ( ! b>omet]4 ,n[ let u consid] !   
balloon z a globule ( moi/ure ( a       
def9ite weight1 & ?is globule only "o ( 
an aggregation ( globules suffici5t to  
=m a cl\d4 ,we c readily see f :at has  
gone be=e t a cl\d ?us =m$1 hav+ a      
def9ite d5sity & weight1 w\ld float     
high] "s days ?an o!rs4  ,assum+ aga9 t 
! d5sity ( ! air rema9s ! same f day to 
day1 ! cl\ds w /ill float high or l[ 9 !
 atmosph]e f ano!r cause4 ,let u g back 

to our illu/ration ( ! balloon4 ,if we h
 a fix$ condition ( atmosph]e1 ext]nal  
to ! balloon1 & v>y ! conditions        
int]nally1 :i* means v>y+ its weight1 ! 
balloon w float high] or l[] z ! int]nal
 conditions are v>i$4 ,n[ apply ?is     
pr9ciple to ! moi/ure globules ( :i* a  
cl\d is =m$ & we c und]/& :y a cl\d w   
float high or l[ f ! two causes t we h  
describ$4 ,cl\ds are ( diff]5t color &  
d5sity1 & ?is is due to ! diff]5ces ( ! 
make-up ( ! moi/ure globules ( :i* !    
cl\ds are =m$4 ,if ^! globules are 9 an 
advanc$ /age ( cond5sation ! cl\d is    
d>k] & m opaque4 ,9 e>li] conditions (  
cond5sation ! cl\d w h a bright look1   
:i* %[s t x reflects mo/ ( ! light1     
:]eas 9 ! case ( ! d>k cl\d ! light is  
l>gely absorb$4  ,!re is a sort ( notion
 prevail+ t cl\ds come up f ! horizon1 &
 9 _m cases !y d1 b !y may =m directly  
ov] our heads4 ,!re always has to be a  
beg9n+1 & t occurs :]ev] ! conditions   
are mo/ favorable = cond5sation ( vapor4
 ,if ! e>? is wet & ! sun is hot !      

evaporation may be v rapid z well z !   
asc5t ( ! invisible moi/ure1 :i* c>ries 
) x ! air1 :i* 9 turn exp&s ! high] x   
rises1 ?us produc+ cold4 ,?is1 tak5 ) ! 
normal cold t exi/s 9 ! high] regions1  
may be suffici5t to produce a sudd5     
cond5sation ( ?is asc5d+ vapor1 :i* is  
all t is necess>y to =m a cl\d4  ,!     
inquiry may arise1 ,:y is ! moi/ure     
cond5s$1 almo/ always1 9 ! upp] regions 
( ! air1 :]e x is r>e8 ,because ! m r>e 
& !re=e exp&$ x is1 ! m moi/ure x w     
hold4 ,?is1 tak5 ) ! fact t cold curr5ts
 are enc\nt]$ high up1 suffici5tly      
answ]s ! "q4  ,x is int]e/+ to "k t !   
processes ( nature are int]dep5d5t4 ,x  
is n en\gh t we h ! evaporation (       
moi/ure t w asc5d into ! high] regions (
 ! air & !re be cond5s$ into cl\d &     
possibly ra91 b we mu/ h ! means =      
di/ribut+ ^! conditions ov] a l>ge area1
 & = ?is purpose we h ! ph5om5on ( w9d4 
,:y ! w9ds bl[ c be acc\nt$ = to a c]ta9
 ext5t1--we might say to a l>ge         
ext5t1--b !re yet rema9 _m unsolv$      

problems relat+ to w9d & wea!r4 ,( !    
ph5om5a ( w9d we w speak m fully 9 a    
future *apt]4     ,,*apt] ,,ix4  ,,cl\d 
,,=mation--,,cont9u$4   ,z wat] 9 its   
cond5s$ /ate is #hae times heavi] ?an   
air1 ! "q naturally comes to "o :y x    
does n imm$iately fall to ! e>? :5 x    
cond5ses4 ,!re are at lea/ two &        
probably m /ages ( cond5sation4         
,inve/igators into ! ph5om5on ( cl\d    
=mation claim to h asc]ta9$ t ! fir/    
effect ( cond5sation is to =m little    
globes ( moi/ure t are holl[1 l a       
bubble1 ) v ?9 walls4 ,ev]yone has      
recogniz$ ! ease ) :i* a soap bubble w  
float 9 ! air1 & yet x is simply a film 
( moi/ure4 ,^! little balloons1 s to    
speak1 are call$ sph]ules4 ,x is        
und\bt$ly ! case t m+l$ ) ^! little     
bubbles ( moi/ure !re are f9e p>ticles (
 solid wat] hang+ on & c>ri$ along ) !m4
 ,und\bt$ly ?is is true2 at lea/ j be=e 
! f9al act ( cond5sation takes place2 & 
:5 ! little holl[ sph]ules collapse !y  
are ga!r$ toge!r 9 drops ( wat] l>g] or 

small] accord+ to ! rapidity (          
cond5sation4 ,!re is probably ano!r p[] 
at "w to prev5t ! too ready             
precipitation ( moi/ure :5 cond5s$1 & t 
is ! w9d4 ,a cl\d nev] /&s /ill1 al?\gh 
9 "s cases x may appe> to d s4 ,if we   
take a /one 9 our h& & all[ x to drop   
)\t apply+ any =ce to x1 x w fall       
directly to ! gr\nd4 ,b if we give x an 
impetus 9 a horizontal direction x w    
travel "s di/ance be=e /rik+ ! gr\nd4   
,if we c\ld give ! same impetus to a    
body z light z a globule ( wat]-du/ x   
w\ld probably travel indef9itely )\t    
fall+4 ,du/ t w\ld settle directly to ! 
gr\nd f an elevation 9 /ill air w\ld    
travel ?\s&s ( miles )\t fall+1 be=e a  
w9d hav+ any consid]able velocity4      
,suppose ! sun to be %9+ ) int5se heat  
^u a c]ta9 area ( ! e>?'s surface & !   
conditions to be "r = v rapid           
evaporation ( moi/ure4 ,! air :i* is    
heat$ close to ! gr\nd1 be+ exp&$1 w    
rise1 toge!r ) ! invisible p>ticles (   
moi/ure1 & !re w be a column (          

moi/ure-lad5 air cont9ually asc5d+ until
 x rea*es a po9t 9 ! upp] atmosph]e :]e 
x is cond5s$ into a cl\d t takes on !   
bill[y =m :i* 9 summ] "t we call a ?und]
 cl\d1 b :i* 9 ! sci5ce ( meteorology is
 call$ cumulus1 or heap-cl\d4 ,if !re 7 
no air curr5ts ?is bill[y cl\d w\ld /& z
 ! capp+ ( an invisible pill> ( asc5d+  
vapor1 b z x is nev] ! case t air is n  
mov+ at "s velocity 9 ! upp] regions1 x 
floats away z rapidly z x is =m$4 ,?is  
peculi> k9d ( cl\d is =m$ 9 !           
mid-regions ( ! atmosph]e1 & x is a     
summ] cl\d z well z a l& cl\d4 ,( c\rse1
 x may float (f ov] ! ocean & ma9ta9 its
 peculi> %ape = a c]ta9 di/ance1 b x is 
r>e t su* a cl\d w\ld ev] be se5 9      
mid-ocean or 9 midw9t]4 ,z ! w>m season 
advances 9 summ]1 & evaporation f ! e>? 
is less ?an ! ra9fall1 !re is less &    
less moi/ure 9 ! air1 :51 ( c\rse1 !    
conditions = cl\d =mation1 especially   
inl&1 are n s favorable z 9 ! e>ly spr+ 
or summ]4 ,frequ5tly !re comes a "t :5  
we h a long season ( dry1 settl$ wea!r4 

,probably dur+ mo/ ( ! days cl\ds w =m &
 we ?9k x is go+ to ra91 b be=e night !y
 h vani%$1 & ! same ?+ is repeat$ ! next
 day & ! next1 p]haps = weeks at a "t4  
,! explanation is ?is3 ,we h already    
said t s long z ! air rema9s 9 a uni=m  
condition z to temp]ature x w absorb    
moi/ure 9 a transp>5t /ate until x is   
fill$ to ! measure ( its capacity at a  
giv5 temp]ature4 ,if !re 7 no *ange (   
temp]ature1 x w\ld n cond5se into cl\d4 
,cl\ds may be absorb$ into !            
atmosph]e--or evaporat$--& become       
invisible2 & ?is process is go+ on to a 
great] or less degree cont9ually4 ,if we
 wat* ! /eam z x escapes f a /eam boil]1
 ! fir/ effect is cond5sation into cl\d1
 b z x floats away x gradually melts &  
is absorb$ into ! atmosph]e z invisible 
vapor4 ,?is is especially true on a w>m 
day2 ! same process takes place 9 ! air 
t is go+ on at ! level ( a body ( wat]  
or at ! surface ( moi/ e>?4  ,z be=e    
/at$1 cond5sation always takes place :5 
a body ( moi/ure-lad5 air comes 9       

contact ) cold4 ,:5 ! /eam escapes f a  
boil]1 ev5 on ! hotte/ day1 x is hott]  
?an ! surr\nd+ air2 ! fir/ effect is    
cond5sation1 & !n evaporation takes     
place ! same z x w\ld at ! surface ( !  
e>? :5 ! cond5s$ p>ticles ( moi/ure are 
sep>at$ into ! invisible atoms t        
accompany evaporation4  ,9 settl$1 dry  
wea!r z ! sun approa*es ! z5i?1 ! e>?   
becomes int5sely heat$1 & !re is an     
asc5d+ column ( air p>tly lad5 )        
moi/ure2 b n to ! same ext5t z e>li] 9 !
 season4 ,cond5sation takes place &     
cl\ds are =m$1 b z !re is n suffici5t   
moi/ure to c>ry !m to ! po9t ( a fur!r  
cond5sation1--:i* w\ld result 9         
precipitation1--z ! sun l[]s 9 ! we/ & !
 heat$ air becomes m ev5ly di/ribut$ ?is
 cond5s$ vapor is reabsorb$ into ! air z
 invisible moi/ure by a process alli$ to
 t ( evaporation4 ,?is condition ( ?+s  
w\ld ext5d to a mu* long] p]iod ?an x   
does 9 our latitude if x 7 n = ! gradual
 *ang+ ( ! seasons1 :i* f9ally de/roys !
 balance 9 ! dynamics ( cl\d-l& & all[s 

! cold--t has be5 held back = ! "t--9 ! 
great nor!rn zone to get ! upp] h&4 ,!n 
we h :at is t]m$ 9 common p>lance a     
*ange 9 ! wea!r1 or1 m prop]ly 9 ?is    
case1 a *ange 9 ! season4  ,we h already
 spok5 ( ! cl\d call$ cumulus 7:i* means
 heap7 & ( its p]=mance dur+ ! dry      
season ( summ]4 ,!re is ano!r =m ( cl\d 
t is se5 at ?is season ( ! ye> call$    
cirrus 7a curl74 ,x takes ! =m ( a curl 
at its ends4 ,?is cl\d usually has a    
?read$ %ape & sometimes takes ! =m ( a  
fea!r1 & frequ5tly =ms are se5 t rem9d y
 ( fro/ pictures on a w9d[ pane4 ,^!    
cl\ds float v high 9 ! atmosph]e1 away  
above ! tops ( ! highe/ m\nta9s1 f six  
to eight miles above ! level ( ! sea4   
,!y are =m$ only at a season ( ! ye> :5 
! atmosph]ic conditions are mo/ uni=m4  
,at c]ta9 times ( ! day & night !       
moi/ure w rise to ?is height be=e x     
cond5ses & :5 x does cond5se x          
imm$iately freezes1 :i* makes x take on 
^! peculi> =ms t w\ld no d\bt con=m v   
closely to ! fro/ pictures on ! w9d[    

pane if x 7 n = ! di/urb+ influ5ces (   
air curr5ts at ?is altitude4 ,! fact t  
!y are ice or fro/ cl\ds in/ead ( wat]  
cl\ds gives !m t peculi> :it5ess &      
brightness ( appe>ance4 ,if ord9>y cl\ds
 are wat]-du/ ^! high cl\ds may be call$
 ice-du/4 ,sometimes we see !m ly+ 9 b&s
 or ?reads runn+ across ! sky 9 !       
direction t ! w9d bl[s4 ,_! =m is       
und\bt$ly a resultant ( ! /ruggle betwe5
 ! air curr5ts & ! t5d5cy ( cry/alliz$  
wat] to arrange itself 9 c]ta9 def9ite  
l9es or =ms4 ,?is cl\d may be said to be
 "o extreme1 hav+ its home 9 ! highe/   
regions ( cl\d-l&1 :ile ! cumulus1 or   
?und] cl\d1 is ! o!r extreme & occupies 
! l[] or mid regions ( ! air4  ,!re is a
 /ill l[] cl\d ( c\rse1 z ord9>y fog is 
no?+ m ?an cl\d1 :i* "u c]ta9 conditions
 lies on ! surface ( ! ocean or dry l&4 
,fogs prevail :5 ! b>omet] is l[4 ,z    
soon z x rises f ! s\rce ( evaporation !
 moi/ure cond5ses almo/ to ! po9t (     
precipitation4 ,!re is n en\gh buoyancy 
9 its globules :5 ! air is light1 z x is

 :5 we h a l[ b>omet]1 to cause ! fog to
 float into ! high] regions ( !         
atmosph]e4  ,! high cl\ds1 :i* are call$
 cirrus1 "u c]ta9 conditions drop d[n to
 :]e !y beg9 to melt into ord9>y moi/ure
 globules1 & :ile ?is process is go+ on 
we h a comb9$ cl\d effect :i* is call$  
cirro-/ratus4 ,?is =m ( cl\d may be     
recogniz$1 :5 look+ (f t[>d ! horizon1  
by its be+ =m$ into long /raight b&s4 ,x
 is sometimes call$ ?read-cl\d4 ,z x    
fur!r desc5ds x takes on a diff]5t =m   
call$ ! cirro-cumulus1 or curl-heap4    
,?is is j ! opposite 9 its appe>ance to 
! cirro-/ratus1 z x is brok5 up into    
flocks ( little cl\ds sep>at$ f ea* o!r 
& 9 ! act ( *ang+ to ! =m ( ! cumulus1  
or bill[y =m ( cl\d2 & ?is latt] takes  
place :5 x drops to a /ill l[] /ratum ( 
w>m] air & is !re call$ ! cumulo-/ratus1
 :i* is ! =m ( cl\d we mo/ (t5 see 9 !  
season ( ?und]/orms4 ,! l[] edge ( !    
cl\d is /raight1 p>allel ) ! horizon1   
:ile ! upp] "p is made up ( great bill[y
 masses1 hav+ high lights ^u _! well    

def9$ projections & bl5d+ into d>k]     
%ades caus$ by ! %ad[s 9 ! valleys      
betwe5 ! m\nta9s ( cl\d4  ,! ra9 cl\d is
 call$ ! nimbus1 & may be said to be !  
ext5sion ( a cumulo-/ratus4 ,:5 x rea*es
 ?is condition x is cond5s$ to a po9t   
:]e ! vesicul> globules collapse & a    
numb] ( !m run toge!r1 =m+ a solid drop 
( wat]1 & "h x beg9s to fall4 ,x may be 
v small at fir/1 b 9 its fall o!r       
cond5s$ globules w adh]e to x & if !    
conditions are "r1 sometimes ! ra9 drops
 w h ! diamet] ( a qu>t] ( an in* by !  
"t !y rea* ! e>?4  ,"u o!r conditions1  
su* z we h sometimes dur+ dry wea!r1 !  
ra9 drops w />t to fall1 b in/ead ( gr[+
 l>g]1 !y gr[ small] by absorption into 
! ?ir/y air1 & w n be all[$ to rea* !   
e>?4 ,(t5 !re are %[]s ( ra9 9 ! air t  
fall to a c]ta9 di/ance & are tak5 up1 z
 9 ! process ( evaporation1 to aga9 be  
=m$ into cl\d1 )\t ev] hav+ t\*$ ! e>?4 
,?us x w be se5 t cl\ds assume v>i\s =ms
 "u v>i\s conditions ( atmosph]e1 z x is
 relat$ to moi/ure1 temp]ature1 &       

d5sity4 ,cl\ds sometimes appe> to be    
/ation>y :5 !y are only cont9ually =m+  
on "o side & cont9ually be+ absorb$ into
 invisible moi/ure on ! o!r4 ,i rememb] 
see+ "s wond]fully beautiful cl\d       
effects 9 ! regions ( ! ,alps4 ,almo/ e 
day 9 summ] !re appe>s above ! peak (   
,m\nt ,blanc a beautifully =m$ cl\d cap 
/&+ "s di/ance above x & holl[$ out     
und]nea? l an inv]t$ cup4 ,al?\gh ?is   
cl\d appe>s to be /ation>y1 x is und]go+
 a rapid *ange2 ! moi/ure rises f !     
sn[-capp$ peak z invisible vapor to a   
c]ta9 di/ance1 :]e x is cond5s$ into a  
cl\d ( wond]ful brilliancy4 ,z ! cl\d   
globules float upw>d !y are absorb$ into
 ! atmosph]e aga91 z invisible moi/ure  
at ! upp] limit ( ! cl\d4 ,if ! w9d     
happ5s to be bl[+1 ano!r ph5om5on takes 
place1 giv+ ! appe>ance some:at ( a     
volcano4 ,x is bl[n (f f ! peak 9 !     
direction ( ! w9d1 b )9 a %ort di/ance x
 /rikes a w>m] /ratum ( air1 :]e x is   
absorb$ & assumes ! transp>5t condition4
  ,if we asc5d a high m\nta91 we get "s 

idea ( ! altitude ( ! v>i\s =ms ( cl\d4 
,a ?und]/orm may be 9 progress f> bel[  
u1 :ile ! sun may be %9+ f a cle> sky   
above1 ) p]haps ! exception ( ! fro/    
cl\ds t we h ref]r$ to float+ high above
 ! m\nta9 tops4  ,we h n[ describ$ 9 a  
g5]al way h[ cl\ds are =m$1 h[ !y are   
cond5s$ into ra91 & h[ moi/ure is       
di/ribut$ ov] l>ge areas by ^! ra9 cl\ds
 be+ borne on ! w+s ( ! w9d2 & n[ y ask1
 ,:5ce ! w9d8 ,9 our next & foll[+      
*apt]s we w try to answ] ?is "q4        
,,*apt] ,x4  ,,w9d--,,:y ,,x ,,bl[s4    
,we h said t globules ( moi/ure1 releas$
 by ! action ( ! sun's rays 9 ! process 
( evaporation1 t5d to rise because !y   
are light] ?an ! air4 ,"r "h let x be   
said t all mat]ial sub/ances h weight2  
ev5 hydrog51 ! lighte/ kn[n gas1 has    
weight1 & is attract$ by gravitation4   
,if !re 7 no air or o!r gase\s sub/ances
 on ! face ( ! e>? except hydrog51 x    
w\ld be attract$ to & envelop ! e>? !   
same z ! air n[ does4 ,c>bon dioxide is 
a gas t is heavi] ?an ! air4 ,if we take

 a vessel fill$ ) ?is gas & p\r x into  
ano!r vessel x w s9k to ! bottom &      
displace ! air conta9$ 9 x until ! air  
is all driv5 out4 ,if we fill a j> )    
wat] up to a c]ta9 height & !n p\r a p9t
 ( %ot into x ! wat] w be caus$ to rise 
9 ! vessel because x has be5 displac$ at
 ! bottom by ! heavi] mat]ial4 ,n[ if we
 remove ! %ot ! wat] w rec$e to ! level 
ma9ta9$ be=e ! %ot 0 put 94 ,on !       
contr>y1 if we %\ld p\r an equal bulk ( 
cork or pi? balls into ! j> ! wat] w\ld 
n be displac$1 because ! balls are      
light] ?an ! wat] & w\ld lie on top ( x2
 if1 h[ev]1 ! wat] is remov$ f ! j>1 !  
cork w imm$iately g to ! bottom ( ! j>1 
because ! cork is heavi] ?an ! air :i*  
has tak5 ! place ( ! wat]4 ,we wi% to   
impress ^u ! m9d ( ! read] ! fact1 t all
 sub/ances ( a fluidic nature1 :e!r 9 ! 
fluid or gase\s /ate1 h weight1 & obey !
 laws ( gravitation1 & ! heavi] portions
 w always seek ! l[] levels1 & 9 do+ ?is
 w displace ! light] portions1 caus+ !m 
to rise4 ,!re is no t5d5cy 9 any        

sub/ance to rise ( itself1 b ! light]   
sub/ance rises because x is =c$ to d s  
by ! heavi]1 :i* displaces x4 ,?is law  
lies at ! bottom ( all ( ! ph5om5a ( air
 curr5ts4  ,if we are at c]ta9 po9ts on 
! sea%ore 9 ! summ] "t we may notice t  
ab\t #i o'clock 9 ! morn+ a breeze w    
spr+ up f ! ocean & bl[ t[>d ! l&2 ?is w
 increase 9 int5sity until ab\t #b      
o'clock 9 ! aft]noon1 :5 x has rea*$ its
 maximum velocity1 & f ?is "t x         
gradually dim9i%es1 until 9 ! ev5+ !re w
 be a season ( calm1 ! same z !re 0 9 ! 
e>ly morn+4 ,! explanation ( ?is peculi>
 action ( ! air is f\nd 9 ! fact t dur+ 
! day ! l& is heat$ mu* m rapidly on its
 surface ?an ! wat] is4  ,! radiant     
en]gy f ! sun is sudd5ly arre/$ at !    
surface ( ! e>?1 :i* is heat$ to only a 
v %all[ dep?1 :ile 9 ! wat] x is        
diff]5t2 be+ transp>5t x is p5etrat$ by 
! radiant en]gy to a mu* great] dep? &  
does n sudd5ly arre/ x1 z is ! case on  
l&4 ,z ! sun rises & ! rays /rike 9 a m 
& m v]tical direction ! e>? becomes     

rapidly & int5sely heat$ at its surface1
 & ?is 9 turn heats ! /ratum ( air next 
above x1 :i* is press+ on x ) a =ce (   
fifte5 p\nds to ! squ>e in* at          
sea-level4 ,:5 air is heat$ x exp&s1 & z
 x exp&s x gr[s light]4 ,! /ratum ly+ ^u
 ! e>? z soon z x becomes heat$ moves   
upw>d & its place is occupi$ by !       
heavi]1 cool] air t fl[s 9 f ! sides4   
,we c n[ see t if !re is a /rong asc5d+ 
curr5t ( air on ! l& ne> ! ocean ! cool]
 air f ! surface ( ! ocean w fl[ 9 to   
take ! place ( ! w>m] & light] air t is 
driv5 upw>d1 really by ! =ce ( gravity  
:i* causes ! heavi] fluid to keep ! l[e/
 level4 ,z ! e>? gr[s hott] ?is movem5t 
is m & m rapid1 :i* causes ! fl[ ( cold]
 air to be quick5$1 & h5ce ! increas+   
=ce ( ! w9d z ! sun m\nts high] 9 !     
heav5s4 ,b :5 x has pass$ ! po9t (      
maximum heat+ int5sity & ! e>? beg9s to 
cool by radiation1 ! movem5ts ( air     
curr5ts beg9 to sl[ up1 until along 9 ! 
ev5+ a po9t is rea*$ :]e ! surface ( !  
e>? & t ( ! ocean are ( equal           

temp]ature1 & !re is no long] any cause 
= *ange ( position 9 ! air4  ,! e>?     
heats up quickly1 & x also cools        
quickly1 especially if !re is gre5 grass
 & vegetation4 ,:ile !y are poor        
conductors ( heat1 !y are excell5t      
radiators1 s t :5 ! sun's rays are no   
long] active ! e>? cools d[n rapidly &  
soon passes ! po9t :]e !re is an        
equilibrium betwe5 ! l& & wat]4 ,! wat] 
possesses ! opposite quality4 ,x is sl[ 
to become heat$1 because ( a mu* l>g]   
mass t is affect$1 & is equally sl[ to  
give up ! heat4 ,& ! consequ5ce is t    
aft] ! sun has set1 ! l& cools s mu*    
fa/] ?an ! wat] t we soon h ! opposite  
condition1 & ! sea is w>m] ?an ! l&1 :i*
 makes ! air at t po9t light]1 & :i* 9  
turn causes ! d5s] or cold] air f ! l&  
to fl[ t[>d ! ocean1 & displace ! light]
 air & =ce x upw>d2 h5ce we h a l&      
in/ead ( a sea breeze4 ,s t ! normal    
condition 9 summ] is t ( a breeze f !   
ocean t[>d ! l& dur+ "p ( ! day & a     
correspond+ breeze f ! l& to ! ocean    

dur+ "p ( ! night1 ) a p]iod ( no w9d   
dur+ ! morn+ & ev5+ ( ea* day4  ,! =ces 
t "w to produce all ! v>y+ ph5om5a ( air
 curr5ts on diff]5t portions ( ! e>? are
 difficult to expla91 z !re are s _m    
local conditions ( heat & cold1 & ^! are
 modifi$ by ! advanc+ & rec$+ seasons4  
,! unequal di/ribution ( l& & wat] ^u ! 
e>?'s surface2 ! read9ess ) :i* "s      
portions absorb & radiate heat z comp>$ 
) o!rs2 ! tall ranges ( m\nta9s1 _m ( !m
 sn[-capp$2 ! l[l&s adjac5t to !m t     
become int5sely heat$ "u ! sun's rays2 !
 div]sity ( coa/l9e & ! fact t !re is a 
zone ( cont9ually heat$ e>? & wat] 9 !  
tropical regions--all ^! conditions1    
c\pl$ ) ! fact t ! e>? rotates on its   
axis once 9 tw5ty-f\r h\rs1 are c]ta9ly 
suffici5t to acc\nt = all ! complicat$  
ph5om5a ( a]ial *anges on ! v>i\s       
portions ( ! e>?'s surface4  ,! trade   
w9ds are s call$ because !y bl[ 9 a     
c]ta9 def9ite direction dur+ c]ta9      
seasons ( ! ye>1 & c be reckon$ ^u = !  
use ( comm]ce4 ,if y trace ! l9e ( !    

equator y w notice t = m ?an ?ree-qu>t]s
 ( ! di/ance x passes ?r\gh ! wat]4 ,!  
wat]1 z we h expla9$ 9 ! la/ *apt]1     
becomes gradually heat$ to a consid]able
 dep?1 & :5 once saturat$ ) heat is sl[ 
to give x up4 ,x c easily be se5 t !re w
 be a zone ext5d+ ea* way f ! equator = 
a c]ta9 di/ance t w become m int5sely   
heat$ ?an any o!r p>ts ( ! e>?1 ) !     
exception ( c]ta9 circumscrib$ portions 
( ! l&4 ,! result is t ?is heat$        
equatorial zone is con/antly s5d+ up w>m
 air caus$ by ! inru% ( cold] air1 :i*  
is heavi] ?an ! air at ! equator1 exp&$ 
by ! heat4 ,! w>m air at ! equator is   
=c$ up into ! high] regions ( !         
atmosph]e1 & "h x ov]fl[s ea* way1 nor? 
& s\?1 caus+ a curr5t ( air 9 ! upp]    
regions c\nt] to t ( ! l[]4 ,z x travels
 nor? & s\? x gradually drops z x       
becomes cool]1 & f9ally at "s po9t nor? 
& s\? its c\rse is *ang$ & x fl[s 9 aga9
 t[>d ! equator4 ,z a matt] ( fact1 !   
trade w9ds d n fl[ app>5tly f ! nor? &  
s\? directly t[>d ! equator1 b 9 an     

oblique direction4 ,on ! nor? side ( !  
equator we h a nor!a/]ly w9d1 & a       
s\!a/]ly w9d on ! s\? side4 ,?is is     
caus$ by ! rotation ( ! e>? f we/ to    
ea/4 ,! direction ( ! trade w9d1 h[ev]1 
is m app>5t ?an real4  ,! e>? 9 its     
diurnal revolutions travels at ! rate ( 
a little m ?an #ajjj miles an h\r at !  
equator4 ,b if we %\ld travel nor?w>d to
 )9 f\r miles1 say1 ( ! nor? pole1 !    
surface po9t w\ld be mov+ at ! rate (   
only ab\t a mile an h\r4 ,at "s po9t    
equidi/ant betwe5 ! nor? pole & !       
equator ! surface ( ! e>? w be mov+ at a
 rate1 say1 ( #ejj miles an h\r4 ,if we 
c\ld fire a projectile f ?is po9t t w\ld
 h a c>ry+ p[] to take x to ! equator "s
 "t aft] ! projectile 0 fir$1 al?\gh x  
w\ld fly 9 a p]fectly direct l9e1 x w\ld
 appe> to anyone at ! equator :o obs]v$ 
its approa* to be mov+ f a nor!a/]ly    
direction4 ,! reason is t ! e>? is      
travel+ twice z fa/ at ! equator z x is 
at ! po9t :5ce ! projectile is fir$4    
,!re=e x w ov]%oot1 s to speak1 at !    

equator1 & n be dragg$ ar\nd by !       
increas$ motion we f9d !re4  ,to make   
?is /ill pla9]1 suppose ! e>? to be /&+ 
/ill & a projectile be fir$ directly    
across f ! nor? pole 9 ! direction ( !  
l9es ( longitude & requir$ "o h\r to    
rea* ! equator1 ! projectile w\ld appe> 
to anyone /&+ at ! equator to come      
directly f ! nor?4 ,if1 h[ev]1 ! e>? is 
revolv+ at ! rate ( #ajjj miles an h\r  
at ! equator to ! ea/w>d1 & ! projectile
 0 fir$ f ! pole1 :]e !re is practically
 no motion1 9 ! same direction along !  
longitud9al l9es z be=e1 ! obs]v] w\ld h
 to be 9 a position on ! equator #ajjj  
miles we/ ( ?is longitud9al l9e 9 ord]  
to see ! projectile :5 x arriv$2 !re=e !
 app>5t movem5t ( ! projectile w\ld n be
 along ! l9e at ! in/ant t x 0 fir$1 b  
along a l9e t w\ld cross ! equator at a 
po9t #ajjj miles we/4 ,:5 a s\?w>d      
impulse is giv5 to ! air x foll[s1 to "s
 ext5t1 ! same law1 s t to "o /&+ on !  
equator ! nor!rn trade w9d w bl[ f !    
nor!a/ & ! s\!rn trade w9d f ! s\!a/4   

,ow+ to ! fact t ! air rises 9 ! heat$  
zone !re is always a region ( calms at  
?is po9t :]e !re is no w9d & no ra94    
,!re are two o!r regions ( calms 9 !    
ocean1 "o at ! nor? at ! tropic ( ,canc]
 & ano!r at ! s\? ne> ! tropic (        
,capricorn4 ,z has be5 /at$1 !re are    
curr5ts fl[+ back 9 ! upp] regions at ! 
equator nor? & s\?1 & ^! are call$ !    
upp] trades--! l[] curr5ts be+ call$ !  
l[] trades4 ,^! upp] trades gradually   
fall till !y rea* ! tropic ( ,canc] on !
 nor?1 :]e ! l[] "p ( ! curr5t /ops &   
b5ds back t[>d ! equator1 n[ becom+ a "p
 ( ! l[] trade w9d4 ,?is causes a calm  
at t po9t :]e x turns4 ,! upp] p>ts (   
?is curr5t cont9ue on1 9 a nor!rly &    
s\!rly direction1 on ! surface until !y 
meet ) ! cold air ( ! nor? & s\? pol>   
regions1 :]e !re is a conflict ( !      
elem5ts--z !re always is :5 cold & w>m  
curr5ts meet4  ,! only po9t :]e ! trade 
w9d has free play is 9 ! ,s\? ,indian   
,ocean1 & ?is is call$ ! he>t ( !       
trades4  ,if ! :ole globe 7 cov]$ ) wat]

 !re w\ld be a m con/ant condition (    
temp]ature2 b ow+ to ! great diff]5ce   
betwe5 ! l& & wat]1 bo? z to altitude & 
! ability to absorb & radiate heat1 we h
 all ( ^! v>i$ & complicat$ conditions (
 w9d & wea!r4 ,! trade w9ds %ift f nor? 
to s\? & vice v]sa ) ! advanc+ & rec$+  
seasons1 due to ! fact t ! e>? has a    
comp\nd motion4 ,x n only revolves on   
its axis once 9 tw5ty-f\r h\rs1 b x     
rocks back & =? once a ye>1 :i* is      
gradually *ang+ ! direction ( its axis2 
& 9 addition to ^! motions x is travel+ 
ar\nd ! sun z well4     ,,*apt] ,,xi4   
,,w9d--,,cont9u$4   ,9 our la/ *apt] we 
discuss$ ! w9ds t prevail 9 ! regions ( 
! tropics call$ trade w9ds1 because !y  
foll[ a direct c\rse ?r\gh ! ye>1 ) !   
exceptions not$ 9 reg>d to _! %ift+ to !
 nor? or s\? ) ! *ang+ seasons2 we also 
describ$ ! ph5om5a ( l& & sea breezes1  
:i* dur+ c]ta9 seasons ( ! ye> rev]se _!
 direction twice daily4 ,we w n[        
describe ano!r k9d ( w9d1 call$         
monsoons1 t prevail 9 ,india4  ,india   

lies directly nor? ( ! great ,indian    
,ocean1 & ! l[] "p ( x comes )9 !       
tropical belt ly+ s\? ( ! ,tropic (     
,canc]4 ,dur+ ! summ] season "h ! e>?   
/ores m heat dur+ ! day ?an x radiates  
or loses dur+ ! night4 ,?is causes ! w9d
 to bl[ 9 a nor!rly direction f ! sea   
bo? day & night = six mon?s ea* ye>1 f  
,april to ,octob]4 ,dur+ ^! mon?s ! l&  
is cont9ually heat$ day & night to a    
high] temp]ature ?an ! wat] 9 ! ocean   
s\? ( x4 ,! w9ds are probably n s sev]e 
dur+ ! night z ?r\gh ! day1 z ! diff]5ce
 betwe5 ! temp]ature ( ! l& & ! wat] w n
 be s great dur+ ! night2 & diff]5ce (  
temp]ature betwe5 two po9ts usually     
means a proportional diff]5ce 9 !       
velocity ( ! w9d4 ,!re is a "t 9 ! fall 
& spr+1 :ile !re is a /ruggle betwe5 !  
temp]ature ( ! l& & wat] = supremacy1 :5
 ! w9ds are v>iable1 att5d$ ) local     
/orms some:at z we h !m 9 ! temp]ate    
zone4 ,b aft] ! sun has mov$ s\? to a   
suffici5t ext5t ! l& ( ,india loses m   
heat at night ?an is /or$ up 9 ! day2   

h5ce ! conditions dur+ ! w9t] mon?s are 
rev]s$1 ! wat] is con/antly w>m] ?an !  
l&1 & !re is a con/ant w9d bl[+ f ! l&  
to ! ocean1 :i* cont9ues until ,april1  
:5 aft] a season ( local /orms !        
conditions are e/abli%$ 9 ! opposite    
direction4 ,^! w9ds are call$ monsoons4 
,! ^w monsoon is probably d]iv$ f an    
,arabic ^w mean+ seasons4 ,x is a       
peculi>ity ( ?is monsoon t 9 summ] x    
bl[s 9 a nor!a/]ly direction f ! sea & 9
 ! w9t] 9 a s\?we/]ly direction f ! l&4 
,?is div]g5ce f a direct nor? & s\? is  
caus$ by ! rotation ( ! e>? & !         
explanation is ! same z t we h giv5 = ! 
trade w9ds4  ,9 ! s\!rn latitudes !re is
 a comp>atively con/ant condition ( w9d 
& wea!r1 because ! surface ( ! globe 9  
^! regions is mo/ly wat]2 b 9 ! nor?1   
:]e mo/ ( ! l& surface is locat$1 we h a
 v diff]5t & a v complicat$ set (       
conditions1 z comp>$ ) ! s\!rn zones4   
,! freaks ( w9d & wea!r t we f9d        
prevail+ ^u ! ,nor? ,am]ican cont95t are
 n s easily acc\nt$ = z ! ph5om5a       

h]et(ore discuss$4 ,9 ! nor!rn "p ! l&  
rea*es f> up t[>d ! nor? pole1 :ile on !
 we/ lies ! ,pacific ,ocean1 :i* m]ges  
into ! ,arctic ,ocean at ,b]+ ,/rait4 ,!
 climate ( ! we/]n coa/ is affect$ by a 
w>m ocean curr5t t sets up z f> nor? z  
,alaska1 :ile high ranges ( m\nta9s     
prev5t ! effects ( ?is w>m curr5t f be+ 
felt inl& to any great ext5t2 all ( :i* 
helps to complicate any !ory t may be   
advanc$ reg>d+ *anges ( wea!r4 ,aside f 
! *anges ( temp]ature t are due to !    
seasons1 :i* are caus$ by ! oscillat+   
motion ( ! e>? betwe5 ! limits ( !      
,tropic ( ,canc] on ! nor? & ! ,tropic (
 ,capricorn on ! s\?1 !re are o!r *anges
 con/antly tak+ place 9 all seasons ( ! 
ye>4 ,:ile x is n difficult to acc\nt = 
! *ange ( seasons & ! gradual *ange (   
temp]ature t w\ld naturally foll[--ow+  
to ! diff]5ce ( angle at :i* ! sun's    
rays /rike ! e>?--x is m difficult to   
acc\nt = ! viol5t *anges t occur sev]al 
times dur+ ! progress ( a season1 z well
 z ! less viol5t ones t come e few days4

 ,9 fact1 x r>ely happ5s t ! temp]ature 
is exactly ! same on any two successive 
days dur+ ! ye>4 ,! diurnal *anges are  
easily acc\nt$ = by ! rotation ( ! e>?  
on its axis ea* day4 ,b !re is ano!r    
class ( ph5om5a ) :i* ! wea!r man has to
 /ruggle :5 he is mak+ up a =eca/ ( !   
wea!r f day to day4  ,9 ord] t we may   
proce$ intellig5tly1 let u say a ^w ab\t
 ! b>omet]4 ,we speak ( high & l[       
b>omet]1 & we make ! in/rum5t )         
graduations m>k$ = all k9ds ( wea!r1 :i*
 really mean b v little4 ,! read+ ( a   
s+le b>omet] alone w give u b a fa9t    
idea ( :at is really go+ to happ5 f day 
to day4 ,b if we h a s]ies ( b>omet]s   
locat$ at diff]5t /ations scatt]$ all   
ov] ! cont95t & connect$ at headqu>t]s  
by telegraph1 s t we c h ! read+s f a   
:ole s]ies ( b>omet]s at once1 !n x     
becomes a v useful in/rum5t4 ,a b>omet] 
may read l[ at "o /ation by ! scale1 b  
may be high ) ref]5ce to "s o!r b>omet] 
t reads v l[4  ,:at is a b>omet]8 ,if we
 %\ld take a glass tube clos$ at "o end1

 ! area ( ! cross section ( :i* is "o   
in* squ>e1 & fill x ) m]cury1 & :ile ?us
 fill$ plunge ! op5 end into a vessel ( 
m]cury1 x w be f\nd t ! am\nt ( m]cury  
rema9+ 9 ! tube above ! level ( ! m]cury
 9 ! vessel w weigh ab\t fifte5 p\nds1  
if ! exp]im5t has be5 p]=m$ at          
sea-level4 ,?is w v>y1 h[ev]1 accord+ to
 ! temp]ature ( ! air4 ,( c\rse b>omet]s
 are te/$ :5 ! air is at a c]ta9        
temp]ature4 ,if ! weight ( m]cury 9 !   
tube is fifte5 p\nds1 s9ce x is su/a9$  
by ! air press+ d[n on ! m]cury 9 ! op5 
vessel1 x %[s t ! air-pressure on t op5 
vessel is equal to fifte5 p\nds to !    
squ>e in*4 ,9 practice1 ( c\rse1 ! tubes
 are made v mu* small]4 ,if ! air *anges
 s t x is light] ?an normal ! m]cury w  
fall 9 ! tube1 because ! pressure on !  
m]cury 9 ! op5 vessel is less ?an fifte5
 p\nds to ! squ>e in*4 ,&1 aga91        
conditions may arise t w cond5se ! air &
 make x = ! "t be+ weigh m ?an fifte5   
p\nds to ! squ>e in*1 9 :i* case !      
m]cury w rise 9 ! tube4 ,?us x w be se5 

t ! b>omet] w regi/] ! slighte/ *ange 9 
air pressure4  ,let u dwell = a mom5t on
 ! causes ( :at are commonly call$      
*anges ( wea!r1 :5 we w aga9 rev]t to ! 
use ( ! b>omet]4  ,! use ( ! telegraph 9
 connection ) ! e/abli%m5t ( a wea!r    
bureau hav+ /ations = obs]vation at     
conv5i5t po9ts ?r\gh\t ! c\ntry has     
contribut$ mu* to ! sci5ce (            
meteorology4 ,x is f\nd t !re are areas 
( high & l[ pressure exi/+ at ! same "t 
9 diff]5t p>ts ( ! c\ntry4 ,^! usually h
 _! orig9 9 ! f> nor?we/1 & foll[ ea*   
o!r1 sweep+ d[n ! ea/]n side ( ! ,rocky 
,m\nta9s & gradually b5d+ ea/]ly & f t  
to nor!a/]ly by ! "t !y rea* ! ,atlantic
 coa/4 ,! areas ( l[ pressure are call$ 
cyclones1 :ile ! areas ( high pressure  
are call$ anti-cyclones4 7,by cyclone we
 d n mean ^? cl\d funnels commonly call$
 by t "n t =m at c]ta9 times ( ! ye> 9  
c]ta9 sections ( ! c\ntry & produce su* 
de/ruction ( life & prop]ty4 ,^! /orms  
are usually conf9$ to a n>r[ /rip & are 
%ort-liv$4 ,!y arise und\bt$ly f local  

conditions4 ,a description ( ^!         
tornadoes--= su* is _! true "n--w be    
giv5 9 "s future *apt]47  ,^! c5t]s (   
high & l[ pressure may be sev]al hundr$ 
miles ap>t4 ,9 ! area ( high pressure1  
if x is 9 ! w9t] season1 ! wea!r is     
unusually cle> & cold1 & g5]ally cle> & 
fairly cool at any season1 & :ile !re   
may be "s w9d x is n s /rong z 9 !      
cyclone or l[-pressure c5t]4 ,at ?is    
po9t x w be w>m] & w9ds w prevail1 ) ra9
 or sn[1 ! w9ds v>y+ 9 direction &      
int5sity at a giv5 po9t z ! cyclone     
moves =w>d4 ,9 ! c5t] ( ^! cyclones &   
anti-cyclones !re w be a region (       
comp>ative calm1 & ! air is asc5d+ at ! 
c5t] ( ! area ( l[ pressure :ile x is   
p\r+ 9 on all sides f ! area ( high     
pressure :]e ! air is compress$ by a    
d[nw>d curr5t f ! upp] regions4  ,!     
high-pressure or anti-cyclone sy/em     
usually cov]s a l>g] area ?an !         
l[-pressure sy/em1 :]e ! air is asc5d+4 
,:ile ! air moves lat]ally f high to l[1
 x does n move 9 a direct l9e4 ,! air   

movem5t outside ( ! high-pressure c5t]  
is usually n at a v high spe$1 b 9      
nor!rn latitudes 9 ! direction ( ! h&s (
 a clock4 ,z x circles ar\nd x wid5s out
 spirally until x rea*es ! edge ( a     
l[-pressure sy/em1 :5 x b5ds 9 its c\rse
 & moves 9 ! o!r direction ar\nd ?is    
c5t]1 b con/antly mov+ inw>d t[>d x 9 a 
spiral =m & 9 a direction t is rev]se to
 t ( ! h&s ( a clock4 ,:5 ! air curr5t  
comes )9 ! influ5ce ( a l[-pressure or  
cyclonic sy/em ! velocity ( its movem5t 
is v mu* accel]at$ until x has mov$ into
 ! zone ( quiet air 9 ! c5t]1 :]e x is  
asc5d+4  ,9 ! upp] regions ( ! atmosph]e
 !re are c\nt] curr5ts fl[+ 9 ! opposite
 direction4 ,! d[nw>d fl[ at ! area (   
high pressure compresses ! air ne> !    
surface ( ! e>? & r>efies x 9 ! high]   
regions ( ! atmosph]e1 :ile ! opposite  
effect is go+ on ov] ! c5t] ( l[        
pressure1 ! air be+ r>efi$ ne>] !       
surface ( ! e>?1 b cond5s$ above normal 
9 ! high] regions by ! upw>d curr5t1 :i*
 causes an ov]fl[ back t[>d ! r>efi$    

upp] regions ov] ! area ( high pressure4
  ,x w be obs]v$ t ! ord9>y /orm has a  
comp\nd motion4 ,! :ole sy/em moves 9 an
 ea/]ly direction1 :ile ! w9ds are bl[+ 
spirally ab\t ! /orm c5t]4 ,if we %\ld  
be 9 ! track ( a mov+ /orm s t its c5t] 
pass$ ov] u ! w9ds at ! beg9n+ w\ld bl[ 
9 "o direction & !n !re w\ld come a     
subsid5ce until x _h mov$ =w>d ?r\gh !  
quiet zone1 :5 we %\ld feel ! w9d 9 !   
opposite direction until ! area ( l[    
pressure _h mov$ =w>d into ! region (   
high pressure4 ,! velocity ( ! w9d w be 
det]m9$ by ! diff]5ce ( pressure betwe5 
! areas & by ! di/ance t ! areas ( high 
& l[ pressure are ap>t4 ,! /eep] ! grade
 ! m rapidly ! fluid w fl[4  ,let u n[ h
 rec\rse1 = a mom5t1 to ,figs4 #a1 #b1 &
 #c 9 ord] t ! subject may be m fully   
und]/ood4 ,9 look+ at ^! diagrams we    
%\ld imag9e ourselves look+ ,s\?1 ) !   
left h& to ! ,ea/4  ,illu/ration3 ,,fig4
 #a4  ,fig4 #a %[s ! g5]al direction ( !
 air movem5t betwe5 two areas--"o ( high
 & ! o!r ( l[ pressure4 ,! arr[s %[ !   

g5]al direction ( ! w9d4 ,y w notice t 9
 ! upp] regions x bl[s 9 an opposite    
direction f ! air movem5t on ! surface (
 ! e>?4  ,fig4 #b %[s 9 a g5]al way h[ !
 w9d moves spirally ar\nd bo? c5t]s4    
,ov] ! area ( high pressure ! air       
desc5ds spirally f ! upp] regions1      
circl+ ar\nd a l>ge area--x may be "o   
hundr$ miles or m 9 diamet]--9 !        
direction ( ! movem5t ( ! h&s ( a clock4
  ,illu/ration3 ,,fig4 #b4  ,b !n ! w9d 
at ! high-pressure area is light] ?an x 
is at ! l[1 & circles outw>dly until x  
f9ally moves (f 9 ! direction ( a       
l[-pressure area1 gradually b5d+ 9 ! o!r
 direction until f9ally x moves ! rev]se
 ( ! h&s ( a clock--al?\gh n[ x is 9 a  
small] circle1 & ) a m rapid motion4 ,x 
moves spirally & upw>dly ab\t !         
l[-pressure area until x rea*es a po9t 9
 ! upp] air1 :]e x goes ?r\gh ! same    
gyrations 9 an opposite direction4 ,n[  
imag9e ! :ole comb9ation mov+ f we/ to  
ea/ at an av]age rate ( ?irty miles p]  
h\r1 & imag9e fur!r t ?is sy/em is l9k$ 

to o!r sy/ems t are foll[+ along1 & y h 
"s idea ( ! wea!r *anges z !y occur 9 ! 
middle ,unit$ ,/ates4  ,by ref]r+ to    
,fig4 #c y w see :y ! w9d *anges its    
direction :5 a /orm c5t] passes ov] any 
po9t4 ,x has n only a spiral b also a   
=w>d movem5t4  ,illu/ration3 ,,fig4 #c4 
,n[ let u g back to ! b>omet] & see :at 
"p x plays 9 pr$ict+ *anges 9 ! wea!r4  
,at ! area ( l[ pressure ! air is       
asc5d+1 z we h se51 &1 ow+ to ! peculi> 
way x asc5ds--by circl+ spirally upw>d  
ar\nd a region ( comp>ative calm--x     
creates a p>tial vacuum1 :i* is m       
pron\nc$ 9 ! c5t] ( ! area4 ,at ! area (
 high pressure ! air w be cond5s$ by !  
desc5d+ curr5t be+ arre/$ by ! e>?4 ,!  
desc5d+ curr5t--com+1 z x does1 f ! upp]
 & cold] regions--acc\nts = ! cool wea!r
 t mo/ always prevails at a             
high-pressure area4 ,9 ord] to "k h[    
great ! *ange ( wea!r is likely to be1  
we mu/ "k :at ! read+s ( at lea/ two    
b>omet]s are--"o at ! high- & ano!r at !
 l[-pressure area4 ,if ! diff]5ce betwe5

 ! read+s ( ! two b>omet]s is v great1 &
 ! areas are comp>atively close toge!r1 
we may expect ! *ange to be sudd5 &     
viol5t4  ,high & l[ z appli$ to a       
b>omet] are only relative t]ms4 ,!re is 
no fix$ po9t on ! index ( ! in/rum5t t c
 be said to be arbitr>ily high or l[4 ,=
 ?is reason a s+le b>omet] is n ( mu*   
use4 ,if x beg9s to fall f any po9t1 &  
falls rapidly1 x indicates t an area ( a
 mu* l[] pressure is approa*+4 ,! same  
is true ( a high-pressure area1 if !    
b>omet] rises rapidly f any po9t4  ,if  
we /udy ! air motions 9 ^! sy/ems       
suffici5tly to get at lea/ an inkl+ ( ! 
law ( _! movem5ts1 x becomes a v int]e/+
 subject4  ,w9d f :atev] cause s]ves a  
wond]fully useful purpose 9 ! economy ( 
nature4 ,)\t w9d1 heat & moi/ure c\ld n 
be di/ribut$ ov] ! face ( ! e>? & our   
globe w\ld n be a fit habitation = man4 
,h[ wond]ful is ! ma*9]y ( ,nature1 t c 
fir/ =ge a _w into %ape & aft]w>d       
decorate x ) gre5 grass & fl[]s t are   
wat]$ by ! e>ly & latt] ra96     ,,*apt]

 ,,xii4  ,,local ,,w9ds4   ,!re are s _m
 causes t w produce air motion t x is   
(t5 difficult to det]m9e j :at "o is !  
*ief factor 9 caus+ ! direction ( ! w9d 
at any p>ticul> "t4 ,!re are v _m       
in/ances1 h[ev]1 :]e ! cause c be trac$ 
)\t difficulty2 _m ( ^! h already be5   
m5tion$ & !re are _m m t might be4 ,(   
c\rse1 z has be5 (t5 /at$1 !re is only  
"o remote cause = all w9ds1 & t is !    
sun1 c\pl$ ) ! movem5ts ( ! e>?4 ,b !re 
are c]ta9 local conditions t are        
cont9ually modify+ ! ph5om5a ( air      
movem5t4 ,! velocity ( w9ds z !y occur f
 day to day v>ies v greatly ) ! height  
above ! surface ( ! e>?2 ord9>ily !     
velocity at #ajjj feet above ! e>? w be 
m ?an ?ree times great] ?an x is at #ej 
or #fj feet above1 & ev5 at #fj feet !  
velocity is mu* great] ?an at ! surface 
( ! e>?4 ,?is is due p>tly to ! ret>d+  
effect ( friction caus$ by contact ( !  
air ) ! e>?'s surface1 b m p>ticul>ly by
 trees1 inequality ( surface1 & o!r     
ob/ructions on ! e>?4  ,!re is a v>iety 

( w9d call$ m\nta9 w9ds t arise f       
diff]5t causes4 ,z has be5 /at$ 9 a =m] 
*apt]1 "u ord9>y conditions ! air is m  
d5se at sea-level ?an at any po9t above1
 & ! d5sity is con/antly *ang+ f d5s] to
 r>] ! high] we asc5d4 ,suppose at a    
c]ta9 po9t1 say halfway up a m\nta9     
side1 ! air has a c]ta9 d5sity1 & if x  
is at re/ ! l9es ( equal d5sity or      
pressure w seek a level1 j z wat] w\ld  
"u ! same conditions4 ,suppose we />t at
 a giv5 po9t on ! side ( a m\nta9 & run 
out on a level till we are #ajj feet 9 a
 p]p5dicul> l9e above ! side ( ! m\nta91
 ! air conta9$ )9 ^? l9es w be 9 ! %ape 
( a triangle4 ,if n[ ! sun %9es ^u !    
side ( ! m\nta9 ! air is w>m$ & exp&s   
accord+ to a well-kn[n law1 & ! am\nt ( 
expansion w dep5d ^u ! dep? ( ! volume (
 air2 h5ce ! po9t ( greate/ expansion 9 
our figure w be :]e ! air is #ajj feet  
deep1 & w gradually decrease z we g t[>d
 ! m\nta9 till we come to ! po9t :]e our
 horizontal l9e makes contact ) ! m\nta9
 side4 ,at t po9t1 ( c\rse1 !re is no   

expansion1 because !re is no dep? ( air2
 & ! effect w be t ! exp&$ air w ov]fl[ 
t[>d ! m\nta91 & be deflect$ up its     
slop+ side4 ,if we apply ?is same       
pr9ciple to ! :ole m\nta9 side we c see 
t !re w be1 dur+ ! day1 a con/ant curr5t
 ( air fl[+ up ! m\nta94 ,z night comes 
on ?is upw>d movem5t w cease & !re w be 
a season ( quiet until ! e>? has become 
cold] ?an ! air1 & we h a ph5om5on (    
exactly ! opposite k9d1 :5 ! air        
contracts in/ead ( exp&s1 :i* produces a
 d[nw>d curr5t f ! m\nta9 top4  ,^!     
curr5ts are z regul> at c]ta9 seasons ( 
! ye> z ! l& & sea breeze4 ,( c\rse1 !y 
may be oblit]at$ = ! "t be+1 by !       
pres5ce ( a /rong] w9d due to "s o!r    
cause1 su* z dur+ ! preval5ce ( a /orm4 
,9 "s ( ! regions ( ,cali=nia hotte/    
dur+ ! day "t1 ! nights are made        
endurable1 & ev5 delightful1 by ! cool  
breezes t sweep d[n f ! tops ( !        
m\nta9s4 ,x (t5 happ5s t on ! %ady side 
( a high & /eep m\nta9 :]e ! sun's rays 
/rike x s obliquely1 if at all1 t ! e>? 

w be b little heat$1 !re w be a va/ mass
 ( cold air /or$ up4 ,aft] ! valley has 
become int5sely heat$ by ! sun !re is an
 asc5d+ curr5t ( air :i* 9 turn causes a
 d[n ru% ( ! cold body ( air f ! m\nta9 
side4 ,^! local w9ds are frequ5tly v    
sev]e1 only la/+1 h[ev]1 = a %ort "t1   
until an equilibrium ( temp]ature &     
d5sity has be5 e/abli%$4 ,a wond]ful    
exhibition ( ?is sort ( w9d is said to  
occur at c]ta9 times ( ! ye> on ! coa/  
at ,ti]ra del ,fuego1 :]e a bla/ :i* !y 
call ! ,williwaus1 comes d[n f ! m\nta9 
side1 )\t w>n+1 ) su* trem5d\s =ce t no 
%ip c\ld /& ! /ra9 if x %\ld cont9ue =  
any l5g? ( "t4 ,=tunately ! %ock does n 
la/ m ?an eight or t5 seconds1 :5 x is  
foll[$ by a p]fect calm4 ,x is z ?\gh a 
great volume ( air _h be5 fir$ f "s     
enorm\s cannon f ! top ( ! m\nta9 to !  
sea4 ,! wat] is pulv]iz$ into a spray t 
is driv5 9 e direction4  ,sometimes ^!  
viol5t bla/s occur 9 ! ,alps1 b f a v   
diff]5t cause4 ,avalan*es ( great ext5t 
(t5 take place on ! sides ( ! m\nta9s1  

:5 a va/ am\nt ( mat]ial1 equal to ?ree 
or f\r hundr$ million cubic feet ( e>?1 
w fall sev]al ?\s& feet4 ,(t5 an        
avalan*e ( ?is k9d w produce a w9d1 :i* 
is conf9$1 ( c\rse1 to a re/rict$ area1 
t is said to be s viol5t z to te> "o's  
clo!s into %r$s4 ,?is is n caus$ by any 
diff]5ce ( temp]ature1 b by a viol5t    
compression4  ,!re is a peculi> w9d t   
occurs 9 ,switz]l&1 (t51 betwe5 ! mon?s 
( ,novemb] & ,m>*4 ,^! w9ds la/ f two to
 ?ree days & are ( great                
viol5ce--especially ne> ! m\nta9s4 ,!y  
are w>m & dry & are caus$ by an area (  
l[ b>omet] & an asc5d+ curr5t ( air     
occurr+ at "s po9t nor? ( ! ,alps1 :i*  
causes ! air f ,italy to fl[ ov] !      
,alp9e range1 caus+ a trem5d\s          
precipitation ( sn[ & ra91 :i* n only   
takes ! moi/ure f ! air1 b sets free 9 !
 =m ( heat ! en]gy t 0 /or$ 9 ! process 
( evaporation1 & ?is1 toge!r ) !        
compression ( ! air z x fl[s d[n ! slope
 ( ! m\nta9s1 makes x hot & dry4 ,?is   
w9d is call$ ! ,fohn4  ,!re is a simil> 

condition ( ?+s exi/+ on ! ea/]n slope (
 ! ,rocky ,m\nta9s :i* has a modify+    
effect ^u ! climate ( p>ts ( ,colorado1 
,wyom+1 ,montana1 also ext5d+ up into   
,briti% ,am]ica4 ,?is w9d1 :i* is "h    
call$ *9ook1 arises f causes simil> to  
^? t are active 9 ,switz]l& t give rise 
to ! fohn w9d4  ,!re is a w9d call$ !   
blizz>d t is felt mo/ ke5ly 9 ,montana &
 ! ,dakotas dur+ ! w9t]1 :i* is exce$+ly
 cold & la/s sometimes = a p]iod ( #ajj 
h\rs4 ,! temp]ature falls at times #cj  
or #dj degrees bel[ z]o & ! w9d ma9ta9s 
a velocity ( f =ty to fifty miles an    
h\r4 ,^! w9ds spread ea/w>d z f> z      
,ill9ois1 b n ) ! same sev]ity1 & !y    
move s\?w>d to ! ,gulf ( ,mexico1       
spread+ ov] ! ,/ates ( ,texas &         
,l\isiana1 & are !re call$ nor!rs4 ,x is
 exce$+ly dang]\s to be caught 9 a      
blizz>d 9 ! ,dakotas1 :]e ! w9d rea*es  
its greate/ velocity & ! cold its l[e/  
temp]ature--especially :5 ! w9d is      
accompani$1 z x frequ5tly is1 by sev]e  
sn[+4 ,by ! "t x rea*es ! ,gulf ,/ates x

 is v mu* modifi$ z to temp]ature1 b x  
is a v disagreeable w9d 9 t portion ( ! 
c\ntry1 because ( ! exce$+ dampness ( ! 
air4 ,"o w\ld be mu* m com=table 9 dry1 
/ill air1 ev5 if x 7 _m degrees bel[    
z]o1 ?an 9 an air freight$ ) moi/ure1   
al?\gh ! temp]ature has n fall5 to !    
freez+ po9t4  ,!re are hot w9ds call$ by
 diff]5t names accord+ to ! localities 9
 :i* !y occur4 ,9 s\!rn ,cali=nia at    
c]ta9 seasons ( ! ye> ! inhabitants are 
afflict$ ) :at !y call a des]t w9d t    
bl[s f ! heat$ regions ( ,arizona t[>d !
 ,pacific ,ocean4 ,! temp]ature         
sometimes rea*es #abj degrees           
,fahr5heit1 & p]sons h be5 kn[n to p]i% 
f ! effects ( ^! hot w9ds 9 op5 boats   
out on ! wat] be=e !y c\ld rea* l&4     
,hot w9ds prevail on ! pla9s ( ,kansas  
dur+ ! mon?s ( ,july & ,augu/ t are     
ph5om5al 9 _! int5sity1 s mu* s t if !y 
7 widespread & ( long cont9uance1 l !   
nor!rn blizz>d1 !y w\ld be att5d$ )     
great loss ( life & de/ruction to       
vegetation4 ,=tunately1 !y come 9 n>r[  

/reaks & 9 mo/ cases d n bl[ m ?an f t5 
to ?irty m9utes at a "t4 ,^! hot belts  
are sometimes n ov] #ajj feet wide1 &   
aga9 !y are z mu* z #ejj4 ,!y are s hot 
& dry t gre5 leaves & grass are r5d]$ z 
dry z p[d] 9 a few m9utes4 ,^! w9ds are 
probably caus$ by ! fact t at ?is season
 ( ! ye>1 :5 ! prevail+ w9d is          
s\?we/]ly1 ! air becomes heat$ to a     
great height1 & are ! result+ effect (  
c]ta9 comb9ations ( air curr5ts 9 !     
high] regions ( ! atmosph]e t =ce !     
already heat$ air t[>d ! e>?4 ,z ! air  
desc5ds x is m & m compress$1 :i* causes
 x to become m & m heat$4 ,we h already 
describ$ ! heat+ effect ( compression ^u
 air z %[n by ! exp]im5t ) ! fire syr+e4
 ,x 0 %[n t air at normal temp]ature    
c\ld be sudd5ly compress$ into s small a
 space t ! cond5s$ heat1 :i* 0 be=e     
diffus$ ?r\gh ! :ole bulk ( air at      
normal pressure1 0 suffici5t to cause   
ignition4 ,a cubic y>d ( air on !       
surface ( ! e>? w\ld occupy a mu* l>g]  
space if c>ri$ a mile above x4 ,f ?is x 

is easy to see t if a volume ( air at t 
height _h a temp]ature ( #gj or #hj     
degrees x w\ld be v hot :5 cond5s$ into 
a v mu* small] volume1 z x w\ld be if x 
7 =c$ d[n to ! surface ( ! e>?4 ,^! w9ds
 are ! result ( "s sup]ior =ce t is     
active 9 ! upp] regions ( ! atmosph]e1  
because x is natural = heat$ air to     
rise1 & ?is is :at happ5s :5 ! p[] t =c$
 x d[n to ! e>? is no long] active to   
hold x !re4  ,ref]5ce has be5 made 9 a  
=m] *apt] to tornado w9ds2 !y are r     
exceptional ph5om5a & n ?or\ghly        
und]/ood4 ,! w9ds seem to bl[ 9 f all   
directions t[>d an area ( v l[ pressure 
at a s+le po9t4 ,! spiral motion t is   
common to all cyclones1 9 a tornado     
seems to be ga!r$ up into a cond5s$ =m1 
l a funnel4 ,! direction ( movem5t is ! 
same z t ( ! cyclone--t is1 9 ! rev]se  
direction to t ( ! h&s ( a wat*4 ,!     
upw>d motion ( ! air inside ( ! funnel  
is at a rate ( ov] #agj miles an h\r4 ,!
 onw>d movem5t ( ! :ole sy/em is ab\t   
?irty miles p] h\r4  ,tornadoes occur ) 

great] frequ5cy 9 ! ,unit$ ,/ates ?an 9 
any o!r section ( ! globe4 ,tornadoes   
seldom occur 9 w9t]1 except p]haps 9 !  
,s\!rn ,/ates4 ,!y are m frequ5t 9 !    
mon? ( ,may ?an at any o!r "t dur+ !    
ye>1 al?\gh !y occur sometimes 9 ,april1
 ,june1 & ,july4  ,betwe5 #ahgj & #ahij 
ab\t sixty-five de/ructive tornadoes    
occurr$ 9 ! ,unit$ ,/ates1 involv+ great
 loss ( life & prop]ty4 ,:5 a tornado   
moves (f ! l& on to ! ocean x may become
 :at is t]m$ a wat]sp\t4 ,^! probably   
nev] orig9ate on ! wat]1 b aft] !y h    
once =m$ may be c>ri$ ov] ! wat] to a   
consid]able di/ance4 ,a tornado 0 nev]  
kn[n to orig9ate on ! %ores ( ,lake     
,mi*igan1 b !re are a few in/ances 7!   
mo/ notable "o be+ ! ,rac9e tornado7 :5 
!y h rea*$ ! lake aft] hav+ travel$ f "s
 di/ant po9t inl&4  ,! ,rac9e tornado--s
 call$ because x de/roy$ a l>ge portion 
( t city--happ5$ fifte5 or m ye>s ago4  
,! tornado orig9at$ ab\t #ajj miles     
s\?we/ ( ,rac9e1 ,wis41 9 nor!rn        
,ill9ois4 ,! funnel-%ap$ cl\d pass$ ov] 

! lake1 b ! tornado "* ( ! /orm 0 brok5 
up be=e x rea*$ ! o!r %ore4  ,:5 a      
tornado passes f l& to wat] x becomes a 
wat]sp\t only :5 ! cl\d-funnel hangs l[ 
en\gh & ! gyratory en]gy is suffici5tly 
great4 ,!re is a great pressure on !    
wat] outside ( ! funnel & almo/ a p]fect
 vacuum inside4 ,?is latt] fact         
contributes l>gely to ! de/ructive p[] (
 ! tornado4 ,:5 a funnel is c5tral ov] a
 build+ a sudd5 vacuum is creat$ outside
 ( x & x bur/s outw>dly f ! int]nal air 
pressure4     ,,*apt] ,,xiii4  ,,wea!r  
,,pr$ictions4   ,to pr$ict ) any great  
accuracy :at ! wea!r w be f day to day  
is a some:at complicat$ problem1 &1 z   
all ( u h reason to "k1 wea!r pr$ictions
 made by ^? :o h ! matt] 9 *>ge & are   
suppos$ to "k all ab\t x (t5 fail to    
come to pass4 ,! real tr\ble is t !y d n
 "k all ab\t x4 ,!re are s _m conditions
 exi/+ t are outside ( ! range (        
b>omet]s1 !rmomet]s1 anemomet]s1 &      
telegraphs t no "o c tell j :5 "s ( ^!  
unkn[n factors w /ep 9 to spoil our     

pr$ictions4  ,9 v _m cases1 p]haps 9 a  
l>ge majority ( !m1 ! pr$ictions made by
 ! wea!r bureau sub/antially come to    
pass4 ,x has be5 /at$ 9 =m] *apt]s t !  
*anges ( wea!r accompany ! movem5ts (   
:at are call$ cyclones & anti-cyclones1 
! cyclone be+ accompani$ by l[ b>ometric
 pressure & ! anti-cyclone by a high]   
"o4 ,! w9ds ( ! cyclone move spirally   
ar\nd ! c5t] ( l[e/ depression ) an     
upw>d tr5d1 ! motions be+ 9 a direction 
rev]s$ to t ( ! h&s ( a clock4 ,9 !     
c5t]s ( high pressure ! curr5t is d[nw>d
 in/ead ( upw>d & ! direction ( ! w9d   
ar\nd x is opposite to t ar\nd !        
l[-pressure area4 ,! fundam5tal factor 9
 pr$ict+ ! wea!r is ! direction (       
movem5t ( ^! areas ( l[ pressure4 ,9    
almo/ all cases ! direction ( movem5t is
 f ! we/ to ! ea/1 b n always 9 a       
/raight l9e4 ,^! movem5ts1 h[ev]1 are   
classifi$ s t aft] ! direction has      
become e/abli%$ "o c pr$ict )           
consid]able accuracy z to :e!r x w move 
9 a curv$ or a /raight l9e4 ,by movem5t 

we d n ref] to ! direction ( ! w9d at   
any p>ticul> po9t1 b ! onw>d movem5t ( !
 :ole cyclonic sy/em1 :i* is usually f  
tw5ty-five to ?irty miles an h\r1 b 9 "s
 cases ! spe$ is mu* great]4  ,n only   
does ! upw>d movem5t ( ! :ole sy/em v>y1
 b ! velocity ( ! w9d ar\nd any giv5    
cyclonic c5t] v>ies4 ,!re are ab\t elev5
 classes ( cyclones t appe> 9 ! ,unit$  
,/ates1 ea* class hav+ its own pa? (    
movem5t & orig94 ,a l>ge numb] ( ^!     
appe> to orig9ate nor? ( ! ,dakotas1 &  
move directly ea/ to ! ,gulf ( ,/4      
,lawr5ce4 ,?ree o!r classes orig9ate on 
ab\t ! same l9e1 a little we/1--say1    
nor? ( ,montana1--mov+ fir/ 9 a s\!a/]ly
 direction1 pass+ ov] ! c5t] ( ,lake    
,mi*igan & b5d+ nor!rly ?r\gh ,lake     
,ont>io & f9ally l&+ 9 ! ,gulf ( ,/4    
,lawr5ce4 ,two o!r classes />t at ! same
 po9t1 "o ( !m go+ z f> s\? z ,c9c9nati1
 & ! o!r z f> s\? z ,montgom]y1 ,ala41 &
 bo? turn+ at ^! po9ts nor!a/]ly to !   
,gulf ( ,/4 ,lawr5ce4 ,two o!r classes  
orig9ate 9 ,colorado1 "o mov+ 9 a       

nor!a/]ly direction slightly curv$1 & ! 
o!r directly ea/4 ,/ill o!rs h _! orig9 
f>!r s\? 9 ! ,gulf ( ,mexico1 & move 9 a
 nor!a/]ly direction4 ,v r>ely !y       
orig9ate 9 ! ,atlantic ea/ ( ,savannah1 
mov+ fir/ 9 a nor?we/]ly direction1 b   
f9ally b5d+ to ! nor!a/4  ,e day !re is 
a wea!r map made up %[+ ! locations ( ! 
high & l[ b>omet]s1 direction ( w9d1    
l9es ( equal pressure1 z well z ^? (    
temp]ature4 ,by /udy f ye> to ye> all ( 
^! ph5om5a h become sy/ematiz$1 s t by  
trac+ an area ( l[ b>omet] f its orig9 9
 its progress ea/]ly x is soon se5 to   
fall "u "o ( ^! classes & we are able to
 pr$ict ab\t :at its c\rse w be4 ,kn[+ !
 spe$ ( its movem5t z well z ! velocity 
( w9d & all ! conditions att5d+ x1 tak5 
9 connection ) ! wea!r conditions 9 !   
region = :i* ! pr$iction is made1 an    
exp]t c ord9>ily =eca/ ) "s degree (    
accuracy4 ,aft] all t c be said1 h[ev]1 
wea!r pr$ictions bas$ ^u maps are & h   
be5 f> f satisfactory4 ,"o :o has be5 a 
close /ud5t ( local conditions = a numb]

 ( ye>s w (t5 pr$ict ) z great accuracy 
z ! wea!r bureau4 ,areas ( l[ pressure  
are foll[$ soon] or lat] by a fall (    
temp]ature2 ?is is especially true 9 !  
w9t] mon?s4 ,sometimes ?is fall is v    
m>k$1 & !n x is call$ a cold wave4 ,^!  
sudd5 *anges ( temp]ature are n ?or\ghly
 und]/ood1 b are suppos$ to be due p>tly
 at lea/ to rapid radiation ( heat into 
! upp] regions1 z ! cle> atmosph]e :i*  
usually att5ds areas ( high pressure is 
favorable to su* a condition4           
,und\bt$ly1 too1 !re are dynamic causes1
 =c+ ! cold] air f ! upp] regions to !  
e>?1 :5 x imm$iately fl[s (f t[>d an    
area ( l[ b>omet]4  ,long-"t pr$ictions 
are purely guesses4 ,!y sometimes guess 
on ! "r side1 & ?is gives !m c\rage to  
make ano!r4 ,x is an old say+ t all     
signs fail 9 dry wea!r4 ,9 "t ( a dr\ght
 x is true t ! indications :i* at ord9>y
 times w\ld be surely foll[$ by a ra9   
are ( no value4 ,:5 a season is once    
e/abli%$1 ei!r z a ra9y season or a dry 
season1 x is likely to p]si/ 9 ?is "*   

until a *ange comes t is produc$ by !   
movem5t ( ! sun 9 its c\rse nor!rly &   
s\!rly1 & ! *ange produc$ f ?is cause   
requires sev]al weeks ( "t4  ,if        
accurate wea!r pr$ictions c\ld be made =
 a long "t 9 advance1 or = ev5 a week1  
!y w\ld be ( incalculable value4 ,b x is
 d\btful if ev] ?is w be br\ght ab\t1 z 
!re are too _m necess>ily hidd5 factors 
:i* ent] into ! calculations4 ,if       
/ations c\ld be e/abli%$ all ov] !      
oceans ) suffici5t frequ5cy1 & an equal 
numb] at a suffici5t altitude 9 ! air1  
,i h no d\bt t mu* t is n[ my/]i\s might
 be made pla94     ,,*apt] ,,xiv4  ,,h[ 
,,dew ,,is ,,=m$4   ,read]1 did y ev]   
live 9 ! c\ntry8 ,7 y ev] awak5$ e>ly on
 a summ]'s morn+ to g = ! c[s8 ,did y   
ev] wade ?r\gh a :eat field 9 ,june--or 
! long grass ( a mead[--:5 ! pe>ly      
dewdrops hung 9 clu/]s on ! be>d$ gra91 
%9+ l brilliants 9 ! morn+ sun8 ,h y n  
se5 ! blades ( grass /udd$ ) diamonds m 
beautiful ?an any t ev] fla%$ 9 ! dazzl+
 light ( a ballroom8 ,if n1 y h miss$ a 

picture t o!rwise w\ld h be5 hung on !  
walls ( y\r memory1 t no "o c\ld rob y  
(4  ,ev]yone has notic$ t at c]ta9 times
 9 ! ye> ! grass becomes wet 9 ! ev5+ & 
gr[s m s till ! sun rises ! next day &  
dispels ! moi/ure1 & ?is :5 no cl\d is  
se54 ,dew is z old z ! fields 9 :i*     
grass gr[s4 ,x 0 z famili> to ! anci5ts 
z x is to u1 & yet x is only ab\t       
?ree-qu>t]s ( a c5tury s9ce ! cause ( x 
has be5 und]/ood4 ,we ev5 yet speak ( ! 
dew fall+ l ra94 ,9 =m] times "s        
sci5ti/s suppos$ t x 0 a f9e ra9 t fell 
f ! high] regions ( ! atmosph]e4 ,o!rs  
suppos$ x to be an emanation f ! e>?1   
:ile /ill o!rs suppos$ x 0 an exudation 
f ! />s4       ,by 8 k ! dep?s are brok5
 up & ! cl\ds      drop d[n dew 7,prov4 
iii4 #bj74  ,! fir/ exp]im5ts c>ri$ on 9
 a sci5tific way 7 by ,dr4 ,wells1 a    
physician ( ,london1 betwe5 ! ye>s #ahaa
 & #ahad4  ,ev]yone has notic$ 9 w>m    
wea!r ! famili> ph5om5on ( wat] cond5s$ 
into drops on ! outside ( a pit*] or    
tumbl] conta9+ cold wat]4 ,?is          

cond5sation is dew4 ,x always =ms :5 !  
conditions are "r1 summ] & w9t]4 ,9 cold
 wea!r we call x fro/4 ,x has be5 /at$ 9
 a =m] *apt] on evaporation t ! capacity
 ( ! air = hold+ moi/ure 9 a transp>5t  
=m dep5ds ^u its temp]ature4 ,if !      
temp]ature is at ! freez+ po9t x w      
conta9 ! #afj? "p ( ! atmosph]e's own   
weight z aque\s vapor4 ,if x is #fj     
degrees ,fahr5heit ! air w reta9 six    
gra9s ( transp>5t moi/ure to ! squ>e    
foot ( air1 :ile at #hj degrees x w     
conta9 ne>ly elev5 gra9s4 ,:5 ! air is  
*>g$ ) ?is vapor to ! po9t ( saturation 
7:i* po9t v>ies ) ! temp]ature7 a slight
 depression ( ! temp]ature is suffici5t 
to cond5se ?is vapor into cl\d or drops 
( wat]4 ,betwe5 #ahab & #ahad ,dr4      
,wells made a s]ies ( exp]im5ts ) flocks
 ( cotton wool4 ,he weigh$ out pieces ( 
equal weight & atta*$ a numb] ( !m to ! 
upp] side ( a bo>d & z _m m to ! l[]    
side1 & expos$ x to ! night air "u v>y+ 
conditions4 ,"o exp]im5t 0 made ) a bo>d
 f\r feet f ! e>?1 s t half ( ! bun*es (

 cotton fac$ ! gr\nd & ! o!r half ! sky4
 ,he f\nd ^u weigh+ ^! aft] a night's   
exposure "u a cle> sky t ! cotton wool  
on top ( ! bo>d _h ga9$ f\rte5 gra9s 9  
weight f ! moi/ure1 or dew1 t _h =m$ ^u 
x1 :ile ! same am\nt ( cotton on ! "u   
side ( ! bo>d _h only increas$ f\r      
gra9s4 ,he tri$ fur!r exp]im5ts by mak+ 
little pap] h\ses1 or boxes1 to cov] a  
c]ta9 portion ( grass or vegetation4 ,he
 f\nd t :ile !re w\ld be a heavy dew on 
! grass outside !re 0 little or none )9 
! inclosure4 ,^! exp]im5ts 7 conduct$ 9 
v>i\s ways & closely wat*$ to see t none
 ( ! ph5om5a 7 9 any way connect$ )     
fall+ ra94 ,x has be5 det]m9$ t         
sub/ances l grass & gre5 leaves ( all   
k9ds1 hay & /raw1 :ile !y are poor      
conductors ( heat1 are excell5t         
radiators4 ,9 ano!r *apt] we h ref]r$ to
 ?is quality ( /raw1 t is tak5 advantage
 ( by ! inhabitants ( hot c\ntries 9 !  
manufacture ( ice & 9 our own l& = /or+ 
x4  ,p]haps ev]yone :o has liv$ 9 !     
c\ntry has notic$ t on a summ]'s morn+  

:5 ! grass is lad5 ) dewdrops a gravel  
walk or a du/y road w be p]fectly dry4  
,?is is due to ! fact t ! gravel w reta9
 heat & n radiate x1 = a mu* long] "t   
?an grass or gre5 leaves4 ,dew beg9s to 
=m ^u ! grass v soon aft] ! sun is set  
because ! mom5t ! sun's rays are )drawn 
! heat is rapidly radiat$ by ! blades ( 
grass1 :i* cools ! e>? "u x & ! air     
above & surr\nd+ x1 s t if ! air is     
any:]e ne> ! moi/ure saturation po9t on 
cool+ at ! surface ( ! gr\nd x w readily
 give up a "p ( its moi/ure1 :i*        
cond5ses 9 drops ^u ! blades ( grass4   
,if ! night is /ill & cle> & !re is mu* 
moi/ure 9 ! air1 ! dew w be heavy1 b if 
! night is cl\dy !re w be little or no  
dew =m$4 ,! cl\ds =m a scre5 betwe5 !   
e>? & ! upp] regions ( ! atmosph]e1 :i* 
prev5ts ! heat f radiat+ to a suffici5t 
ext5t to =m dew4 ,= ! same reason no dew
 w =m "u a light cov]+ spread ov] !     
gr\nd ev5 at "s di/ance above x4 ,!     
cov]+ acts z a scre51 :i* prev5ts ! heat
 f radiat+ to ! dew po9t4 ,f :at has    

gone be=e x w be se5 t if ! atmosph]e is
 n *>g$ ) moi/ure up to ! po9t (        
saturation x w require a great] am\nt ( 
depression ( temp]ature to cause        
cond5sation1 & ?is is :y we usually h   
heavi] dews 9 ,june :5 ! air is m highly
 *>g$ ) moi/ure ?an we d 9 ,augu/ :5 x  
is dry4 ,?is also acc\nts = ! ice cl\ds1
 call$ cirrus1 be+ =m$ s high up 9 !    
atmosph]e dur+ dry wea!r4 ,!re is s     
little moi/ure 9 ! air t x requires a v 
great diff]5ce ( temp]ature to cause    
cond5sation to take place1 & ! necess>y 
depression is n rea*$ 9 ^! cases except 
at an altitude ( sev]al miles4  ,dr4    
,wells has %[n t if we take ! read+ (   
two !rmomet]s on a cle> summ] night1 "o 
( !m ly+ on ! grass & ! o!r susp5d$ two 
feet above x1 we %all f9d t ! "o ly+ on 
! grass w read #h or #aj degrees l[] ?an
 ! "o susp5d$ 9 ! air4 ,if ! night is   
/ill !re w be a cold /ratum ( air next  
to ! e>?1 :i* w n t5d to diffuse itself 
to a v great degree & dew w =m4 ,if1    
h[ev]1 x is cl\dy or ! w9d is bl[+ !re  

is r>ely any =mation ( dew4 ,! reason 9 
! =m] case1 z we h expla9$1 is t !      
radiat$ heat is held d[n to ! e>? 9 a   
measure1 & 9 ! latt] case !re is a      
con/ant *ange ( air2 s t 9 ei!r case no 
"p ( x is all[$ to cool d[n suffici5tly 
to precipitate moi/ure4  ,x is a curi\s 
fact t (t5 !re w be a heavi] dew "u !   
blaze ( a full moon on a cle> night ?an 
at any o!r "t4 ,! moon has no scre5s    
ab\t x ( any k9d to ob/ruct ! free      
radiation ( heat4 ,x is suppos$ to be a 
dead c9d] float+ 9 space & n surr\nd$ by
 an atmosph]e1 s t ! sun's rays h full  
effect ^u x dur+ ! "t x is expos$ to !m1
 & at t "t x becomes heat$ to a         
temp]ature ( some?+ l #gej degrees      
,fahr5heit4 ,= half ! mon?1 say1 ! sun  
is %9+ cont9u\sly ^u all or a "p ( x4 ,9
 o!r words1 ! days & nights ( ! moon are
 ab\t two weeks long4 ,! moon does n    
revolve ^u its own axis l ! e>?1 !re=e !
 same side or a portion ( x is expos$ to
 ! sun = #ad days4 ,dur+ ! "t t ! moon  
is 9 ! e>?'s %ad[ x is suppos$ to fall  

to #ahg degrees bel[ z]o1 :i* is #bai   
degrees bel[ ! freez+ po9t4 ,:5 ! moon  
is full & is heat$ up to ov] #gjj       
degrees !re is suffici5t heat radiat+ f 
x to be felt s5sibly ^u ! face ( ! e>?1 
& x w\ld be felt if x 7 n = ! great     
envelope ( atmosph]e & its att5dant cl\d
 =mations t surr\nd ! e>?4 ,!re are b   
few days 9 summ] :5 !re is n a haze 9 ! 
atmosph]e1 al?\gh we call ! sky cle>1   
:i* int5sifies ! light & gives ev]y?+ a 
w>m] tone4 ,! heat com+ f a full moon on
 a cle> night is absorb$ 9 caus+ !      
aque\s vapors t are p>tly cond5s$ 9 !   
high] regions ( ! atmosph]e1 to be      
reabsorb$ into transp>5t vapor4 ,?is    
cle>s away ! heat scre5 9 ! atmosph]e & 
all[s radiation to g on m rapidly at !  
e>?'s surface1 & ?us cools x to a great]
 ext5t :5 ! moon is %9+ brightly ?an :5 
x is d>k & 9 ! %ad[ ( ! e>?4  ,z we h   
already m5tion$1 ! cold t is produc$ by 
radiation ?r\gh ! blades ( grass & o!r  
radiat+ sub/ances may be indicat$ by    
plac+ "o !rmomet] on ! gr\nd & fix+     

ano!r at "s po9t 9 ! air4 ,sometimes !  
diff]5ce is v m>k$1 am\nt+ to z mu* z   
#bj or #cj degrees4 ,if "u ^! conditions
 a cl\d floats ov]head1 =m+ a heat      
scre51 its pres5ce w be readily notic$  
by a rise 9 ! !rmomet]4 ,radiation into 
! upp] regions ( ! atmosph]e is *eck$1  
:i* causes a sudd5 rise 9 ! temp]ature  
ne> ! surface ( ! e>?4 ,by tak+         
advantage ( ?is pr9ciple ( heat         
radiation f ! e>?'s surface x is a v    
easy matt] to protect t5d] vegetation f 
ev5 q a sev]e fro/1 if x occurs 9 ! e>ly
 fall1 by a slight cov]+1 su* z ?9 pap]4
 ,! pap] w act z a heat scre5 & 9 a     
measure prev5t ! heat f radiat+ f ! e>? 
imm$iately "u x4 ,fro/--:i* ( c\rse is b
 froz5 dew--at ?is season ( ! ye> w =m  
on a /ill autumn night1 al?\gh !        
atmosph]e at "s di/ance above ! gr\nd is
 "s degrees above ! freez+ po9t4 ,!     
reason = ?is w be obvi\s :5 we consid] !
 facts t h be5 set =? conc]n+ ! p[] (   
radiation to produce cold4  ,x has be5  
e/imat$ by meteorologi/s t ! am\nt (    

wat] cond5s$ ^u ! surface ( ! e>? 9 ! =m
 ( dew am\nts to z mu* z five in*es1 or 
ab\t "o-sev5? ( ! :ole am\nt ( moi/ure t
 is evaporat$ into ! air4 ,x w ?us be   
se5 t dew p]=ms an important "p 9       
support+ vegetation4  ,! same op]ation 9
 nature's great work%op t =ms ! dews (  
summ] creates ! fro/s ( w9t]4 ,! moi/ure
 9 cold wea!r is cond5s$ ! same z 9 w>m4
 ,:5 x is cond5s$ at ! surface ( ! e>?  
we h ! ph5om5on ( fro/1 b :5 cond5s$ 9 !
 upp] regions ( ! atmosph]e we h t (    
sn[4  ,heat radiation f ! e>? goes on 9 
w9t]1 :i* is evid5c$ by ! fact t a ?ick 
cov]+ ( sn[ is a great b5efit to        
vegetation z a protection aga9/ !       
injuri\s effects ( fro/4 ,! writ] has   
se5 fl[]s bloom+ abundantly at an       
altitude ( #ab1jjj feet above !         
sea-level1 protect$ only by ! fri5dly   
%elt] ( a sn[bank4 ,9 "s cases ! bloom+ 
fl[]s 7 9 actual contact ) ! sn[4 ,by   
exp]im5t x has be5 det]m9$ t ! e>? "u a 
?ick coat+ ( sn[ is usually w>m] by n9e 
or t5 degrees ?an ! air imm$iately above

 ! sn[ cov]+4     ,,*apt] ,,xv4         
,,hail/ones ,,& ,,sn[4   ,a hail/one is 
a curi\s =mation ( sn[ & ice1 & mo/ ( ! 
l>ge hail/ones are conglom]ate 9 _!     
composition4 ,!y are usually compos$ ( a
 c5t] ( froz5 sn[1 pack$ tightly &      
incas$ 9 a rim ( ice1 & ^u ?is rim are  
irregul> cry/all9e =mations jutt+ out 9 
po9ts at irregul> di/ances4 ,frequ5tly1 
h[ev]1 we f9d !m v symmetrically =m$ z  
to outl9e1 & ! sn[ c5t]s are almo/ )\t  
exception r\nd4 ,hail/ones & hail/orms  
diff] 9 diff]5t climates1 b !y are m    
pron\nc$ 9 ! torrid ?an 9 ! temp]ate    
zone4 ,hi/orians give acc\nts (         
hail/ones ( enorm\s size2 ! v l>ge      
hail/ones be+ und\bt$ly aggregations (  
s+le /ones t h be5 ?r[n toge!r &        
congeal$ 9 ! cl\ds dur+ _! fall to !    
e>?4  ,x is record$ t on ,july #d1      
#ahai1 hail/ones fell at ,baconni]e     
measur+ fifte5 in*es 9 circumf]5ce1 & v 
symmetrically =m$1 ) beautiful outl9e4  
,hail/ones 9 ,india are said to be v    
l>ge--f five to tw5ty times l>g] ?an ^? 

9 ,engl& or ,am]ica--seldom less ?an    
walnuts & (t5 z l>ge z oranges &        
pumpk9s4 ,x is record$ t 9 #ahbf1 dur+ a
 hail/orm at ,c&ei%1 ! /ones p]=at$ !   
ro(s ( h\ses l cannon %ot1 & t a s+le   
mass fell t requir$ sev]al days to melt1
 weigh+ ov] #ajj p\nds4 ,x is fur!r     
record$ t on ,may #h1 #ahcb1 a          
conglom]ate mass ( hail/ones fell 9     
,hung>y a y>d 9 l5g? & ne>ly two feet 9 
?ickness4 ,/ill ano!r in/ance is record$
 ( a hail/one hav+ fall5 9 #ahdi ( ne>ly
 tw5ty feet 9 circumf]5ce4 ,?is hail/one
 is said to h fall5 ^u ! e/ate ( ,mr4   
,m(fat ( ,ord4 ,we w only ask our read]s
 to li/5 to "o m hail/one /ory1 9 :i* x 
is relat$ t dur+ ! reign ( ,tippoo1     
sultan1 a hail/one fell z l>ge z an     
elephant4 ,und\bt$ly "o ( two ?+s 0 true
 reg>d+ ?is latt] /ory2 x 0 ei!r a v    
l>ge hail/one or a v small elephant4 ,! 
hi/orian fails to give ! size ( !       
elephant4 ,!re is no d\bt1 h[ev]1 b t   
hail/ones may adh]e & =m l>ge masses ow+
 to ! viol5t agitation ( ! elem5ts t    

always att5ds a hail/orm4  ,hail/orms   
are almo/ univ]sally att5d$ by con/ant &
 heavy ?und] & lightn+1 toge!r ) viol5t 
w9ds4 ,!y usually occur on a v hot day1 
& :5 ! air is fill$ to saturation )     
moi/ure4 ,:5 ?is is ! case a column (   
air is v highly heat$ at "s po9t1 :5 x  
asc5ds ) great =ce into ! upp] regions (
 ! atmosph]e to a great] altitude ?an is
 common 9 ! case ( ord9>y ?und]/orms4   
,"h x meets ) an int5sely cold body (   
air1 :5 x is sudd5ly cond5s$ & readily  
froz5 z soon z cond5s$1 :i* n only =ms  
hail/ones1 b sets free ! en]gy t has be5
 c>ri$ up 9 ! moi/ure globules4 ,?is    
results 9 frequ5t electrical dis*>ges1  
caus+ great waves ( cond5s$ & r>efi$    
air1 :i*1 9 ! r>efi$ portions1 produces 
/ill m int5se cold2 s t we h !          
conditions = a mighty /ruggle betwe5 !  
elem5ts1 :i* is int5sifi$ by a con/ant &
 t]rific electric cannonade4 ,und\bt$ly 
!re are also :irlw9ds 9 ! cl\d1 simil>  
to ^? t sometimes visit ! e>?1 :i* w\ld 
t5d to ga!r up ! hail/ones & aggregate  

!m into l>ge masses4 ,x is a mighty     
battle betwe5 ! moi/ure-lad51 sup]heat$ 
air1 asc5d+ f ! surface ( ! e>?1 & !    
p[]s resid+ 9 ! upp] regions ( cold4    
,nature is con/antly /ruggl+ to f9d an  
equilibrium ( h] =ces1 & a hail/orm is  
only "o ( ! little dome/ic flurries t   
take place :5 %e is sett+ h] h\se to    
rights4 ,hail/orms are usually conf9$ to
 v n>r[ limits1 & !y c prevail on a gr& 
scale only 9 hot climates1 :]e we h !   
conditions = wide diff]5ces ( temp]ature
 betwe5 ! upp] & l[] regions ( !        
atmosph]e2 &1 also1 :]e ! conditions are
 favorable1 = an enorm\s am\nt (        
absorption ( moi/ure into ! atmosph]e4  
,:5 sn[ is =m$ 9 ! atmosph]e1 !         
conditions are q diff]5t f ^? ( a       
hail/orm2 x is usually 9 a l[] plane ( !
 atmosph]e1 & !re is no viol5t          
commotion1 z is ! case ) ! latt]4 ,a    
volume ( air lad5 ) moi/ure comes 9     
contact ) a cold] volume ( air1 :5      
cond5sation takes place1 z 9 ! case (   
ra91 except t ! moi/ure is imm$iately   

froz54 ,9 ?is case bo? volumes ( air may
 be bel[ ! freez+ po9t1 b "o is v mu*   
cold] ?an ! o!r4 ,if ! sn[ rea*es ! e>? 
x w be because ! air is bel[ ! freez+   
po9t all ! way d[n4 ,sn[ is =m$ at all  
seasons ( ! ye>4 ,we may h a sn[/orm on 
a high m\nta9 :5 we h extreme heat at   
sea-level4  ,9 summ] "t ( c\rse ! sn[   
melts z soon z x falls into a /ratum (  
air ) a temp]ature above ! freez+ po9t1 
& cont9ues its j\rney f t po9t z        
ra9drops in/ead ( sn[flakes4 ,9 !       
=mation ( a sn[flake ,nature does "s (  
h] mo/ beautiful "w4 ,a sn[flake fir/   
=ms ) six ice spangles1 radiat+ f a     
common c5t]4 ,%ort] ones =m on ^! six   
spokes1 /&+ at an angle ( ab\t sixty    
degrees1 on ea* side ( ea* spoke1 ( su* 
l5g? & arrangem5t z to =m a symmetrical 
figure or fl[]4 ,!y d n always take !   
same =m1 b foll[ ! same laws t gov]n !  
=mation ( ice cry/als4 ,! /ructure ( a  
sn[flake may be (t5 f\nd ^u a w9d[ pane 
( a fro/y morn+4 ,"h1 h[ev]1 ! free     
arrangem5t ( ! p>ts ( a sn[ cry/al are  

int]f]$ ) by its contact ) ! w9d[ pane1 
b :ile float+ g5tly 9 ! air !re is !    
utmo/ fre$om = ! play ( nature's =ces z 
!y apply to ! "w ( cry/allization4  ,!  
diff]5ce 9 /ructure ( sn[flakes is      
*iefly due to ! conditions "u :i* !y are
 =m$4 ,if ! moi/ure is froz5 too rapidly
 ! molecul> =ces t are active 9         
cry/allization d n h "t to c>ry out !   
"w1 9 its complet5ess ( detail1 z x w   
:]e ! freez+ process1 z well z ! cond5s+
 process1 goes on m sl[ly4     ,,*apt]  
,,xvi4  ,,meteors4   ,meteors are !     
tramps ( int]planet>y space4 ,!y        
sometimes try to /eal a ride on !       
surface ( ! e>?1 b meet ) c]ta9         
de/ruction ! mom5t !y come )9 ! a]ial   
picket l9e ( our _w's def5se aga9/ ^!   
w&]+ vagrants ( ! air4 ,!y h made _m    
attempts to take ?is e>? by /orm1 z x 71
 & _m m w be made4 ,!y fire _! missiles 
at u by ! millions e ye> ) a spe$ t is  
incr$ible1 b ?anks to ! protect+        
influ5ce ( ! great ocean ( air t        
envelops our globe !y become ! victims (

 _! own velocity4  ,meteors or %oot+ />s
 are z old z ! e>? itself1 & !y are !   
mat]ial ( :i* comets are made4 ,be=e x 0
 det]m9$ :at ^! meteors or %oot+ />s 71 
_m !ories 7 promulgat$ z to _! orig94   
,"o 0 t !y 7 masses ( matt]1 l>ge &     
small1 project$ by volcanic action f !  
face ( ! moon ) su* viol5ce z to be     
br\ght )9 ! attraction ( ! e>?4 ,o!rs   
suppos$ !m to be ! effect ( c]ta9       
phosphoric fluids t emanat$ f ! e>? &   
took fire 9 ! upp] regions ( !          
atmosph]e4 ,?is1 h[ev]1 0 m]e           
speculation & )\t any sci5tific basis ( 
fact4 ,anyone :o has be5 an obs]v] (    
%oot+ />s w h le>n$ t !re are c]ta9     
p]iods ( ! ye> :5 !y are m num]\s ?an at
 o!r times2 notably 9 ,augu/ & ,novemb]4
 ,!n aga9 !re are long] p]iods ( _m ye>s
 ap>t4 ,by p]si/5t obs]vation x has be5 
e/abli%$ t !re are great numb]s ( s*ools
 or collections ( cosmic matt] t fly    
?r\gh int]planet>y space1 hav+ def9ite  
orbits l ! planets4 ,any "o ( ^!        
collections may be scatt]$ ?r\gh        

millions ( miles 9 l5g?4 ,a comet is    
simply "o ( ^! w&]+ collections (       
meteoric /ones hav+ a nucleus or c5t]   
:]e ! p>ticles are s cond5s$ z to give x
 a reflect+ surface some?+ l ! planets  
or ! moon4 ,?is enables u to see !      
outl9e ( ! comet to ! po9t :]e !        
fragm5ts ( matt] become s scatt]$ t !y  
are no long] able to reflect suffici5t  
light to rea* our eyes4 ,! fr+e ( a     
comet1 h[ev]1 may ext5d ?\s&s or ev5    
millions ( miles beyond ! bord]s (      
lum9osity4  ,!re is sc>cely a day or    
night 9 ! ye> :5 m or less ( ^! meteoric
 /ones d n come )9 ! region ( our       
atmosph]e1 & :5 ?is happ5s ! great      
velocity at :i* !y travel is ! means (  
_! own de/ruction4 ,!y become int5sely  
heat$ by friction aga9/ ! atmosph]e j z 
a bullet w :5 fir$ f a gun--only to a   
great] ext5t ow+ to ! great] velocity4  
,!y dis9tegrate into du/ :i* floats 9 ! 
air = a "t1 :5 m or less ( x is         
precipitat$ ^u ! surface ( ! e>?4       
,dis9tegrat$ meteors1 or /> du/1 z !y   

are sometimes call$1 are (t5 br\ght d[n 
by ! ra9 or sn[4 ,mo/ ( ! %oot+ />s t we
 obs]ve are v small1 resembl+ fire-flies
 9 ! sky1 b once 9 a :ile a v l>ge "o is
 se5 mov+ across ! face ( ! heav5s1 giv+
 (f brilliant sc9tillations t trail     
beh9d ! meteor1 mak+ a lum9\s pa? t is  
visible = "s seconds4 ,^! brilliant     
manife/ations are due to "o ( two       
causes4 ,ei!r !re is a v l>ge mass (    
inc&esc5t matt] or else !y are s mu*    
ne>] to u ?an 9 ord9>y cases t !y appe> 
l>g]4 ,x is m likely1 h[ev]1 t x is due 
to ! =m] cause r ?an ! latt]1 f ! fact (
 its app>5tly sl[ movem5t z comp>$ ) !  
small] %oot+ />s4 ,x has be5 det]m9$ by 
obs]vation t ! av]age meteor becomes    
visible at a po9t less ?an #ajj miles   
above ! e>?'s surface4 ,x 0 f\nd z f>   
back z #ahbc t out ( #ajj %oot+ />s     
tw5ty-two ( !m _h an elevation ( ov]    
tw5ty-f\r & less ?an =ty miles2         
?irty-five1 betwe5 =ty & fifty miles2 & 
?irte5 betwe5 sev5ty & eighty miles4 ,x 
0 det]m9$ by ,pr(essor ,h]s*el t out (  

sixty obs]vations ( %oot+ />s ! av]age  
height ( _! fir/ appe>ance 0            
sev5ty-eight miles & _! disappe>ance 0  
at a po9t fifty-?ree miles above ! e>?4 
,x is a matt] ( hi/ory1 h[ev]1 t        
sometimes ^! meteoric /ones desc5d to ! 
surface ( ! e>? be=e !y are entirely    
dis9tegrat$4 ,a f9e specim5 ( ?is k9d is
 to be se5 9 ! ,smi?sonian ,in/itution4 
,!re are ov] =ty specim5s ( ^! a]olites 
7air-/ones7 9 ! ,briti% ,museum1 label$ 
) ! times & places ( _! fall4 ,in/ances 
( fall+ to ! e>? are s r>e t !re is     
little to fe> f ^! w&]+ missiles ( !    
air4 ,we d n rememb] a case :]e life or 
prop]ty has suff]$ f ! fall ( a meteor4 
,?is br+s u to ! consid]ation ( ! "p :i*
 ! great air envelope surr\nd+ ! e>?    
plays z a protection aga9/ _m outside   
influ5ces4 ,= in/ance1 if x 7 n = ! air1
 millions ( ^! meteoric /ones w\ld be   
%[]$ ^u our e>? e ye> & at c]ta9 times e
 day1 :i* w\ld r5d] ! e>? unt5able =    
human exi/5ce4 ,we %\ld be at ! m]cy (  
^? w&]+ comets ^: fr+es /rike our       

atmosph]e m or less deeply at frequ5t   
int]vals4 ,x is n impossible t ! e>? may
 at "s "t pass directly ?r\gh "o1 & yet 
!re is little dang] t 9 su* a case !re  
w\ld be m ?an an unusual display (      
cele/ial fireworks4  ,f ! facts t h be5 
above /at$ x w be app>5t to anyone t !  
numb] ( ^! meteoric /ones 9 ! air is be+
 con/antly r$uc$ by _! con/ant collision
 ) ! atmosph]e & consequ5t r$uction to  
a%es or du/4 ,ano!r conclusion is t !   
e>? mu/ be gradually1 b imp]ceptibly    
p]haps1 increas+ 9 size on acc\nt ( !   
con/ant settl+ ^u its surface ( meteoric
 du/4     ,,*apt] ,,xvii4  ,,! ,,sky ,,&
 ,,its ,,color4   ,9 ! *apt]s on light 9
 ,vol4 ,,ii4 x w be /at$ t we see all   
objects by a reflect$ light1 except ^? t
 are self-lum9\s1 su* z ! sun or any o!r
 s\rce ( light4 ,we see ! moon & _m ( ! 
planets entirely by reflection4 ,!re are
 myriads ( small] objects1 too small to 
be se5 z su*1 ev5 "u a microscope1 t    
/ill h a p[] to reflect light t is      
s5sible to our vision4 ,! air surr\nd+ !

 globe is lit]ally fill$ ) ^!           
microscopic light reflectors4 ,!y s]ve  
to give u a diffus$ light :i* enables u 
to see cle>ly all visible objects4 ,we h
 all notic$ ! effect ( a s+le electric  
arc light1 situat$ at a di/ance f any   
o!r s\rce ( light1 & h[ x ca/s extremely
 d>k %ad[s & v high lights2 s mu* s t x 
is difficult to see an object p]fectly 9
 ?is light1 because ! "p ( an object t  
is "u ! direct rays ( ! lamp is s highly
 illum9at$ t ! %ad[1 by comp>ison1 has !
 effect ( simply a d>k blot )\t =m or   
%ape4 ,_m ( y h notic$ 9 a c\ntry       
village1 :]e ! /reets are light$ )      
electric arc lamps1 :at a diff]5ce !re  
is 9 ! illum9at+ effect betwe5 a cle> & 
a foggy night4 ,:5 !re is a fog1 or :5 !
 cl\ds hang l[ d[n1 we get a reflection 
f ^! :i* t5ds to diffuse & s(t5 ! p[]ful
 light rays t are s5t out by ^! lamps4  
,?is effect is especially noticeable :5 
! night is only mod]ately foggy4 ,ea*   
globule ( moi/ure float+ 9 ! air becomes
 a reflector ( light1 & by myriads (    

reflections & c\nt] reflections ! light 
7:i* on a cle> night is conc5trat$7 is  
diffus$ ov] a l>ge area1 produc+ an     
illum9ation :i* = practical purposes is 
f> sup]ior to t produc$ on a cle> night4
 ,:5 ! latt] condition prevails ! rays (
 light are s int5se on objects          
imm$iately surr\nd+ ! lamps t "o is     
bl9d$2 s t ! places :i* are 9 %ad[ seem 
d>k] ?an !y w\ld be if !re 7 no light at
 all4 ,! only way to prev5t ?is effect  
is to h ! lights s close toge!r t !re w 
be cross lights1 :i* t5d to break up !  
int5sity ( ! %ad[s4 ,?is pr9ciple (     
light diffusion is tak5 advantage ( to  
produce an ev5 illum9ation 9 /ores t are
 light$ only on "o or two sides4 ,?is is
 effect$ by a s]ies ( prisms or reflect+
 surfaces t are ca/ ^u ! panes ( glass4 
,if n[ !re 7 no atmosph]e--or1 to /ate x
 diff]5tly--if !re 7 no float+ sub/ances
 9 ! atmosph]e1 ! sun w\ld produce an   
effect ^u ! e>? simil> to t ( a s+le    
electric light4 ,! lights w\ld be       
extremely high1 & ! %ad[s extremely     

d5se4 ,to "o look+ (f into space1 ! sky1
 in/ead ( hav+ ! blue appe>ance t we    
see1 w\ld h ! effect ( look+ into a     
deep1 d>k abyss )\t illum9ation4        
,tyndall has %[n u by a beautiful       
exp]im5t t if !re be 9 a glass tube a   
mixture ( gases relat$ to ea* o!r 9 a   
c]ta9 way *emically1 !y w comb9e into   
small globules or p>ticles simil> to    
moi/ure 9 ! air4 ,if n[ a beam ( light  
is ?r[n ^u ?is tube & a d>k scre5 put   
beh9d x1 we %all1 9 ! beg9n+ ( !        
exp]im5t1 simply see ! d>k scre54 ,z    
soon1 h[ev]1 z ! molecules ( ! gases h  
comb9$ 9 suffici5t numb]s to produce    
p>ticles ( s5sible size we beg9 to h a  
reflection ( light f !m1 ! color ( :i*  
is con/antly *ang+ z ! comb9+ p>ticles  
gr[ 9 size4 ,at a c]ta9 /age 9 its      
progress ! color :i* ! mixture ( gases  
assumes is a beautiful azure blue1      
rival+ 9 purity ! f9e/ skies ( ,greece  
or s\!rn ,italy4  ,! sun is ! great lamp
 t illum9ates ! _w1 :ile ! atmosph]e1   
:i* is fill$ ) p>ticles ( v>i\s         

sub/ances1 becomes ! %ade ( ! lamp :i*  
diffuses & s(t5s ! light & gives x its  
color tones1 :e!r ( w>m? or coldness4   
,we c\ld n well d )\t ! reflect$ light (
 ! sky4 ,! poetry ( life w\ld be sadly  
m>r$4 ,! beautiful effects ( color &    
purity ( tone w\ld be want+4 ,we ne$ to 
ba! 9 light z mu* z 9 wat]1 & ! "* ( !  
light is almo/ z important z ! "* ( !   
wat]4 ,imag9e a _w ) an atmosph]e devoid
 ( all sub/ances t w\ld 9 any way       
reflect light or give to x s(tness or   
color tone4 ,imag9e a sun or a moon )\t 
visible rays--= )\t a reflect+ atmosph]e
 !re w\ld be none4 ,imag9e a sky t 0 no 
sky at all1 b only a d>k void1 ) no     
protect+ vault4 ,?9k ( ! %ad[s1 s d>k t 
y c\ld see no?+ 9 !m4 ,^! w\ld be "s ( !
 effects t w\ld come f an atmosph]e t _h
 no sky sub/ance 9 x4 ,imag9e ! _w      
light$ by "o great arc light4 ,! reflex 
action ^u ! race liv+ 9 su* a light w\ld
 be any?+ b desirable4 ,! _w w\ld       
develop into an arc-light               
civilization--if "o c imag9e :at t w\ld 

be l2 c]ta9ly "o ( int5sely viol5t      
contra/s4 ,look on ?is picture & let u  
be ?ankful = ! blue sky & gold5 sunsets4
  ,b1 y ask1 :y is ! sky blue8  ,9 "o ( 
! *apt]s on ! subject ( light 9 ,vol4   
,,ii4 ! prop]ties ( soap bubbles are    
discuss$4 ,x is %[n t :5 a film is      
/ret*$ across ! m\? ( a tumbl] held 9 a 
position s t ! film is p]p5dicul>1 by ! 
action ( gravity 7! moi/ure con/antly   
fall+ to ! l[] "p ( ! film7 x w         
cont9ually gr[ ?9n]1 & horizontal b&s ( 
color w appe> ^u x1--fir/ r$1 !n foll[$ 
by ! o!r colors ( ! sol> spectrum1 end+ 
) violet4  ,x is also /at$ t e color (  
light has a def9ite wave l5g?4 ,:]e a b&
 ( blue color appe>s ^u ! film we "k t  
its ?ickness is "r = ! wave l5g? ( t    
p>ticul> color :i* is reflect$ f ! back 
( ! film to ! eye4 ,if we c\ld conceive 
! blue vault ( ! heav5s to be half a    
sph]e ( a soap bubble1 ! color t ! sky  
w\ld appe> to u 7if ! light c\ld be ?r[n
 ^u x f b5ea?7 w\ld be det]m9$ by !     
?ickness ( ?is film4 ,if ! film 0       

#a-aef1jjj ( an in* ! sky w\ld be r$    
in/ead ( blue4 ,to reflect ! o!r colors 
! film w\ld h to gr[ ?9n] = ea* color1 9
 ! progression f r$ to violet4 ,! color 
( ! sky is det]m9$ by a light-reflection
 f m9ute globules ( moi/ure float+ 9 !  
air4 ,if ! sky is blue1 !n ! globules   
mu/ be ( ! "r diamet] to reflect t      
color4 ,! v>i\s t9ts & color+s ( ! sky  
are det]m9$ by :at is f\nd 9 !          
atmosph]e1 & ?is is ! reason :y skies   
diff] 9 color+ & tone 9 diff]5t sections
 ( ! globe4 ,! f9e/ skies are probably  
f\nd 9 semi-tropical regions l s\!rn    
,italy1 ,greece1 & ,cali=nia4  ,9 #ahib 
,i visit$ ,greece 9 ! e>ly "p ( ,june4  
,9 cross+ ! ,adriatic1 f ,br9disi to    
,patras 9 ,greece1 ! r\te 0 ?r\gh !     
,ionian ,isl&s t are gr\p$ along !      
s\?we/]n %ore ( ,albania4 ,! sky 0 )\t a
 cl\d1 & its beautiful blue color 0     
reflect$ 9 ! wat]s ( ! ,adriatic1 & ,i  
nev] %all =get ! impression made ^u my  
s5ses :5 we fir/ came 9 sight ( !       
m\nta9s on ! we/ coa/ ( ,albania4 ,at   

?is po9t !y rise abruptly f ! wat] & are
 color$ ) t peculi> azure haze1 mix$ ) a
 %ad+ ( w>m?1 :i* is an effect t di/ance
 gives 9 ! classic atmosph]e ( old      
,greece4 ,! effect ^u ! behold] is to   
intoxicate ! s5ses & to fill him ) t    
delici\sly poetic feel+ t always comes  
:5 /&+ 9 ! pres5ce ( ! sublime 9 nature4
 ,x 0 n ! m\nta9s !mselves t produc$ !  
effect1 = ,i _h se5 gr&] ?an ^!2 b x 0 !
 sky on ! m\nta9s4 ,:5 we look at a     
di/ant m\nta9 x seems to be p>tly hidd5 
by a peculi> haze t is ! color ( ! sky  
at t "t2 we are really look+ at ! m\nta9
 ?r\gh a portion ( ! sky4 ,:ile 9 ,a!ns 
,i took a trip to ! top ( ,m\nt         
,p5telicus1 :i* sep>ates ! pla9s ( ,a!ns
 on ! s\? f ^? ( ,m>a?on on ! nor?4 ,f !
 summit ( ?is m\nta9 we h a mo/ wond]ful
 view ( ! ar*ipelago ( ! ,a,egean       
,sea--a beautiful map ( blue wat] & br[n
 isl&s t melt toge!r 9 ! di/ance4 ,at   
our feet lay ! hi/oric pla9s ( ,m>a?on1 
& 9 ! di/ance rose ! sn[-capp$ peaks (  
,m\nt ,olympus4 ,x is d\btful if ! _w   

furni%es a m beautiful comb9ation (     
ocean1 isl&1 cont95t1 & sky ?an c be se5
 f ,m\nt ,p5telicus4 ,myriads ( br[n    
isl&s set 9 ! blue/ ( wat]--graceful 9  
outl9e & multi=m 9 %ape--jutt+ headl&s &
 l&-lock$ h>bors--/rong 9 color & outl9e
 9 ! imm$iate =egr\nd1 b gradually melt+
 toge!r 9 ! di/ance1 ! br[n becom+ blu] 
& ! blue a s(t] blue till ! :ole is lo/ 
on ! horizon 9 a sky t %ades back to !  
z5i? 9 an ev]-*ang+ azure t = purity (  
tone baffles all description4  ,:at     
wond] t a p born "u su* skies & ^: eyes 
h fea/$ on su* beauties 9 nature %\ld   
conceive & execute su* a ma/]ful "w (   
art z ! ,p>!non6 ,:ile ! v>iation (     
l&scape1 ! /ret* ( wat] fill$ ) isl&s1 &
 ! m\nta9s capp$ ) et]nal sn[ 7 a       
prom95t "p ( ! picture1 x 0 ! sky ) its 
beautiful color-tones t aft] all gave x 
its wond]ful *>m4  ,! skies 9 a nor!rn  
latitude are cold] & gray]1 due to !    
fact t ne>ly always !re is a c]ta9      
degree ( cond5sation ( moi/ure exi/+1   
:i*1 :ile x does n take ! =m ( a cl\d1  

/ill gives a ton+ to ! sky4  ,!re is no 
d\bt b t ! color-tones ( ! sky h an     
influ5ce ^u ! "* & temp]am5t ( ! p :o   
live "u !m4 ,"u semi-tropical skies !   
poetic nature is m /rongly appeal$ to1 &
 a man is m likely to be controll$ by 8 
dreamy imag9+s ?an 8 cold calculations4 
,we f9d ?is latt] *>act]i/ic prevail+ to
 a great] or less ext5t among ! p :o    
live "u cold] & /]n] skies4 ,if all ^!  
qualities or influ5ces c\ld be comb9$ 9 
! "r way1 ! race w\ld be /rong]         
intellectually & 9 o!r ways4 ,x is      
always dang]\s to a race ( p to be      
develop$ along c]ta9 l9es only4 ,!      
developm5t %\ld be symmetrical4 ,!      
/ronge/ m5 are n ^? :o are simply coldly
 intellectual1 nei!r ^? :o are simply   
emotional & s5tim5tal1 b ^? 9 :om he>t1 
m9d1 & s\l are s relat$ t ea* "o ( ^!   
elem5ts re-en=ces & /r5g!ns ! o!rs4  ,at
 c]ta9 seasons ( ! ye> & 9 c]ta9        
localities x is n uncommon to h         
wond]fully beautiful displays ( color+  
^u ! skies & cl\ds at sunset4 ,! "q is  

(t5 ask$ :y we d n see ^! displays at   
o!r times 9 ! day ?an at sunrise & at   
sunset--= ! same effects are se5 9 !    
morn+1 b !y are n notic$ s (t51 because 
to d s w\ld int]f]e ) ! habits ( !      
av]age man & woman4  ,! reason = ?is    
*ange ( color+ is ! angle at :i* ! sun's
 rays /rike ! cl\ds ( an ev5+ sky1 :i*  
are reflect$ to our eyes4 ,:5 ! sun is  
high 9 ! heav5s x %9es aga9/ ! back ( ! 
cl\ds1 f ! po9t ( view ( a p]son /&+ on 
! surface ( ! e>?4 ,x also %9es a %ort] 
di/ance ?r\gh ! air at midday ?an at    
sunset4 ,at sunset ! rays are able to   
%9e on ! "u side ( a cl\d1 especially if
 x is high 9 ! air4 ,! moi/ure globules 
( :i* ! cl\d is made up are mu* l>g] ?an
 ! transp>5t ones t are uncond5s$ & j z 
!y 7 :5 releas$ 9 ! process (           
evaporation4  ,z we h already se51 !    
reflections f ^! m9ute globules give u !
 blue color+ ( ! sky & are v mu* small] 
9 diamet] ?an a globule t is able to    
reflect ! r$ ray4 ,:5 ^! small globules 
are cond5s$ into cl\d a great numb] are 

comb9$ into "o globule1 & !y are ( all  
sizes1 f ! globule ( evaporation to t ( 
! ra9drop :5 precipitation takes place4 
,we h1 !n1 9 ! v>i\s /ages ( cl\d       
=mation all conditions pres5t = reflect+
 ! v>i\s colors & comb9ations ( colors t
 are f\nd 9 ! sol> spectrum4 ,h5ce x is 
t1 "u c]ta9 conditions ( atmosph]e &    
cl\d =mation1 we see at sunset pa9t$ ^u 
! sky ^? wond]ful comb9ations ( colors1 
m beautiful & delicate 9 %ad+1 m v>i\s 9
 comb9ation & pur] ( tone1 ?an any      
arti/1 h[ev] cunn+ 8 f+]s or brilliant 8
 pigm5ts1 has ev] be5 able to tru?fully 
reproduce4 ,ev5 :5 ! sky is cl\dless x  
(t5 assumes a brilliant hue1 :i* is     
p>tly a reflection f invisible moi/ure  
globules & p>tly due to float+ p>ticles 
( du/ t may h be5 driv5 up f ! surface (
 ! e>?1 or may be ! a%es ( meteorites   
dis9tegrat$ by contact ) ! air4  ,"s    
ye>s ago1 comm5c+ 9 ,augu/1 #ahhc1 !re 0
 a wond]ful exhibition ( r$ skies at    
sunset t la/$ = sev]al h\rs aft]        
twilight ord9>ily disappe>s4 ,?is       

ph5om5on ran ?r\gh a p]iod ( sev]al     
weeks1 gradually fad+ away4 ,x 0 aft]w>d
 det]m9$ t ^! displays 7 occasion$ by   
small p>ticles ( a%es or du/ float+ high
 9 ! air1 t 7 ?r[n (f f ! volcanic      
eruption ( ,krakatoa 9 ! ,isl& ( ,java4 
,by ! g5]al circulation ( ! air ! a%es 7
 c>ri$ to all p>ts ( ! _w1 mak+ a       
circuit ( ! e>? 9 f twelve to ?irte5    
days--:i* %[$ a velocity ( ov] eighty   
miles an h\r4 ,?is is an in/ance ( !    
high velocity ( ! air curr5ts 9 ! upp]  
regions ( ! atmosph]e4 ,! reason :y !   
illum9ation ext5d$ s late 9 ! night 0   
because ( ! great height t ^! p>ticles (
 du/ atta9$4 ,! high] ! reflect+        
surfaces are 9 ! air ! long] !y may be  
se5 aft] sunset4 ,ord9>y twilight is    
caus$ by a reflection ( sunlight f !    
upp] air2 & f its duration z ord9>ily   
obs]v$ x is e/imat$ t ! reflection does 
n proce$ f a po9t m ?an ?irty-six miles 
high4 ,9 ! high] latitudes ! twilight is
 long1 f ! fact t ! sun does n g        
directly d[n1 & if we g f> en\gh nor? ! 

:ole night is twilight4 ,9 ! tropical   
regions ! twilight is %ort] ?an at any  
o!r po9t on ! globe = reasons t are     
obvi\s4 ,! sun !re goes directly d[n &  
is soon hidd5 beh9d ! e>?4  ,!re are o!r
 optical effects to be se5 sometimes on 
! horizon some:at resembl+ twilight4 ,! 
aurora borealis 7nor!rn lights71 :i* we 
describe 9 ,vol4 ,,iii41 is se5 9 !     
nor!rn skies at c]ta9 times1 & has v mu*
 ! appe>ance ( twilight 9 "s ( its      
phases4 ,x is con/antly *ang+1 h[ev]1 & 
is easily di/+ui%$ by anyone :o has     
obs]v$ bo?4 ,^! appe>ances are und\bt$ly
 electrical4 ,!re is ano!r ph5om5on se5 
9 ! arctic regions t causes a b& ( :ite 
light to appe> on ! horizon call$ ice   
bl9k1 & x is caus$ by ! reflections f ! 
great iceb]gs t ab\nd 9 t region4       
,curi\s optical effects are sometimes   
obs]v$ a little aft] sunset 9 ! =m (    
/ream]s or b&s ( light t %oot up into ! 
sky1 sometimes to a great height4 ,^!   
are und\bt$ly due to cl\d ob/ructions t 
p>tially %ut (f ! sun's rays f a "p ( ! 

sky1 b all[ x to %9e ) great] brilliancy
 9 ! pa? ( ^! b&s ( light4  ,x w be se5 
f ! =ego+ t ! sky 9 all ( its phases is 
a product ( sunlight & ! sub/ances t    
float 9 ! air1 includ+ moi/ure1 n only 9
 ! invisible /ate1 b 9 all ! /ages (    
cond5sation1 z well z p>ticles ( float+ 
du/4     ,,*apt] ,,xviii4  ,,liquid     
,,air4   ,air1 l wat]1 assumes ! liquid 
=m at a c]ta9 temp]ature4 ,wat] boils & 
vaporizes at #bab degrees ,fahr5heit    
above z]o1 :ile liquid air boils &      
vaporizes at #cab degrees bel[ z]o4     
,heat & cold are practically relative   
t]ms1 al?\gh sci5ti/s talk ab\t an      
absolute z]o 7! po9t ( no heat71 &      
,pr(essor ,dew> fixes ?is po9t at #dfa  
degrees ,fahr5heit bel[ z]o4 ,o!rs h    
e/imat$ t ! =ce ( ! moon dur+ its long  
night ( half a mon?1 is r$uc$ 9         
temp]ature to six or sev5 hundr$ degrees
 bel[1 :i* is f> l[] ?an ,pr(essor      
,dew>'s absolute z]o4 ,h[ev] ?is may be1
 to an animal t is design$ to live 9 a  
temp]ature ( #gj or #hj degrees         

,fahr5heit1 any temp]ature bel[ z]o w\ld
 seem v cold4 ,if1 h[ev]1 we 7 adapt$ to
 a climate :]e ! normal temp]ature 0    
#cab degrees ,fahr5heit bel[ z]o1 we    
%\ld be sev]ely burn$ if we %\ld sit d[n
 ^u a cake ( ice4 ,su* a climate w\ld be
 impossible = animal exi/5ce1 = ! reason
 t !re w\ld be no air to brea!1 s9ce x  
w\ld all liquefy4  ,liquid air is n a   
natural product4 ,!re is no place on our
 e>? cold en\gh to produce x4 ,if ! moon
 _h an atmosph]e 7:i* x probably has n7 
x w\ld liquefy dur+ ! long lun> night1 =
 heat radiates v rapidly f a planet :5 !
 sun's rays are )drawn f x4  ,z y h     
already surmis$1 liquid air is a product
 ( int5se cold4 ,any me?od t w r$uce !  
temp]ature ( ! air to #cab degrees      
,fahr5heit bel[ z]o w liquefy x4 ,great 
pressure w n d ?is1 = we may compress   
air 9 a /rong vessel until ! pressure on
 e squ>e in* ( ! vessel is #ab1jjj      
p\nds1 or six tons1 & /ill x w n liquefy
 unless ! temp]ature is br\ght d[n to ! 
requir$ degree ( coldness4 ,if ?is is   

done x w *ange f a gas to a liquid1 b w 
occupy z mu* space z be=e1 if x is      
cond5s$ to a pressure ( six tons to !   
squ>e in*4  ,until tw5ty ye>s ago x 0   
suppos$ t oxyg5 & atmosph]ic air 7!     
latt] a mixture ( oxyg5 & nitrog57 7    
fix$ gases & c\ld n be liquefi$4 ,9     
#ahgg1 x is said t ,ra\l ,pictet obta9$ 
! fir/ liquid oxyg51 b only a few drops4
 ,ab\t fifte5 ye>s lat] ,pr(essor ,dew> 
( ! ,royal ,in/itution1 ,london1 succe$$
 9 liquefy+ n only oxyg5 b atmosph]ic   
air4 ,& besides liquefy+ ! air he made  
ice ( x4  ,9 #ahib ,i visit$ ,london1   
:]e ,i met ,pr(essor ,dew>1 :o invit$ me
 to witness an exhibition ( !           
manufacture ( liquid oxyg5--&           
incid5tally liquid air--at ! ,royal     
,in/itution4 ,to me x 0 a mo/ wond]fully
 int]e/+ ev5t4 ,i saw air1 tak5 f !     
room1 gradually liquefy 9 a small glass 
te/ tube op5 at ! top4 ,:5 ! tube 0     
)drawn f ! refrig]at+ *amb] x boil$ by !
 heat ( ! room1 & rapidly evaporat$4 ,we
 light$ a spl9t] ( wood & blew x out1   

leav+ a live sp>k on ! end ( x1 & held x
 ov] ! m\? ( ! tube1 kn[+ t if any?+ l  
pure oxyg5 7 evaporat+ ! spl9t] w\ld    
relight & blaze 7an old exp]im5t ) oxyg5
 gas74 ,at fir/ ! spl9t] w\ld n relight1
 because ! evaporat+ gases 7 a mixture (
 oxyg5 & nitrog5 9 ! proportions to =m  
air4 ,b ow+ to ! fact t nitrog5         
evaporates soon] ?an oxyg51 a second    
trial 0 successful1 = ! spl9t]          
imm$iately began to blaze1 %[+ t ! gas  
evaporat+ !n 0 pure1 or ne>ly pure1     
oxyg54  ,:5 ! liquid oxyg5 0 p\r$ into a
 sauc] & br\ght into proximity ) ! poles
 ( a p[]ful magnet ! liquid imm$iately  
ru%$ out ( ! sauc] & clung to ! magnet  
poles2 %[+ t oxyg5 is magnetic4  ,s9ce t
 "t o!r exp]im5t]s h succe$$ 9 mak+     
liquid air on a comp>atively l>ge scale1
 & ! process is simple :5 we consid] "s 
( ! old me?ods4  ,mr4 ,tripl] ( ,new    
,york1 :o has made liquid air 9 great   
quantities1 does x sub/antially z       
foll[s3 ,fir/1 he compresses air to ab\t
 #bejj p\nds to ! squ>e in*4 ,( c\rse ! 

air is v hot :5 x is fir/ compress$     
because all ! air 9 ! tank has be5 r$uc$
 9 bulk ab\t #aff times1 & all ! heat t 
0 9 ! :ole bulk ( air is conc5trat$ into
 "o-#aff? ( ! space x occupi$ be=e x 0  
compress$4 ,x is #aff times hott]4 ,!re 
are two sets ( pipes runn+ f !          
compressor to a long upright tank call$ 
! liquefi]4 ,^! pipes pass ?r\gh runn+  
wat]1 s t ! compress$ air is quickly    
cool$ d[n to ! temp]ature ( ! wat] 7ab\t
 #ej degrees ,fahr5heit74 ,! pipes--at  
lea/ "o set ( !m--run ! :ole l5g? ( !   
liquefi]1 & mo/ likely are coil$4 ,?is  
set ( pipes conta9s ! air to be         
liquefi$4 ,a second set ( pipes runs to 
! bottom ( ! liquefi]1 :]e !re is a     
valve4 ,by op5+ ?is valve a jet (       
compress$ air is all[$ to play on ! o!r 
set ( pipes1 :5 int5se cold is produc$  
by ! sudd5 expansion ( ! air4 ,?is cold 
air ru%es up ar\nd ! pipe conta9+ ! air 
to be liquefi$ & escapes at ! top1 ?us  
absorb+ ! heat until ! temp]ature is    
r$uc$ to #cab degrees bel[ z]o4 ,!n !   

air liquefies & runs into a receptacle1 
:]e x may be drawn (f at pleasure4  ,x w
 be se5 t a l>ge "p ( ! compress$ air is
 wa/$ 9 cool+ ! rema9d] suffici5tly to  
liquefy4  ,! use to :i* liquid air may  
be put1 advantage\sly1 is an unsolv$    
problem2 b no d\bt x w h a place 9 "t4  
,all great discov]ies d4 ,electricity _h
 to wait a long "t = recognition2 b :at 
a "p x plays n[ 9 ! ev]yday life ( !    
:ole civiliz$ _w6  ,curi\s effects are  
produc$ by ?is int5se cold4 ,meat may be
 froz5 s h>d t x w give (f a musical    
tone :5 /ruck4 ,"h is a po9t] = ! seek] 
( novelties 9 ! l9e ( musical in/rum5ts4
  ,liquid air furni%es a beautiful      
illu/ration ( ! fact t a burn+ gas jet  
is cont9ually =m+ wat] z well z giv+ out
 heat & light4 ,if we put liquid air    
into a tea kettle & hold x ov] a gas    
jet1 ice w =m on ! bottom f ! wat]      
creat$ by ! flame1 & x w freeze s h>d t 
! flame w make no impression ^u x1 o!r  
?an to make ! ice cake gr[ l>g]4        
,al?\gh liquid air is n f\nd 9 nature1 &

 is !re=e call$ an artificial product1 x
 is produc$ by tak+ advantage ( natural 
law4 ,)\t ! intellect ( man x nev] w\ld 
h be5 se5 ^u ?is e>?2 & ! same may be   
said conc]n+ _m ?+s 9 our _w1 bo?       
animate & inanimate4 ,! g5ius ( man is  
,god-l4 ,he lifts ! veil t %r\ds !      
my/]ies ( nature1 & "h he comes 9 v t\* 
) ! m9d ( ! ,inf9ite4 ,man int]prets ?is
 ?\ght ?r\gh ! m$ium ( natural law1 &   
lo1 a new product6  ,h[ mu* life w\ld h 
be5 robb$ ( its *>m & int]e/ if all ^!  
?+s _h be5 work$ out = u f ! beg9n+6 ,= 
!re is no int]e/ s absorb+ & no pleasure
 s ke5 z t ( pursuit :5 ! pursu] is     
rea*+ out aft] ! hidd5 ?+s t are lock$  
up 9 ,nature's great /oreh\se4 ,f "t to 
"t %e yields up h] secrets1 little by   
little1 to enc\rage ^? :o love h] & are 
will+ to "w1 n only = ! pleasure ( !    
gett+1 b = ! highe/ & be/ good ( _!     
fell[s4     ,,wat]4     ,,*apt] ,,xix4  
,,riv]s ,,& ,,floods4   ,wat] cov]s su* 
a l>ge proportion ( ! e>?'s surface & is
 su* an important factor 9 ! economy (  

nature t x becomes a matt] ( int]e/ to  
/udy ! process ( its di/ribution4 ,wat] 
is to our globe :at blood is to our     
bodies4 ,a con/ant circulation mu/ be   
kept up or all animal & vegetable life  
w\ld suff]4 ,"h1 z 9 e o!r op]ation (   
nature1 ! sun is ! great he>t & motive  
p[] t is active 9 ! di/ribution (       
moi/ure ov] ! face ( ! globe4  ,! total 
annual ra9fall on ! :ole surface ( ! e>?
 am\nts to ab\t #bh1jjj cubic miles (   
wat]4 ,only ab\t "o-f\r? ( ?is am\nt ev]
 rea*es ! ocean1 b x is ei!r absorb$ = a
 "t by animal & vegetable life or lift$ 
?r\gh ! process ( evaporation into ! air
 z invisible moi/ure1 :5 x is c>ri$ ov] 
! region ( ra9fall & !re cond5s$ into   
wat] & falls back ^u ! e>?--only to g   
?r\gh ! same op]ation aga94 ,! :ole     
surface ( ! e>? is divid$ into dra9age  
areas t lead ei!r directly ?r\gh        
rivulets & riv]s to ! ocean1 or into "s 
l&-lock$ bas91 :]e x ei!r f9ds an outlet
 "u gr\nd or is kept )9 b\nds ?r\gh !   
process ( evaporation1 ! same z is !    

case ) our great oceans4 ,9 ,nor?       
,am]ica ! am\nt ( dra9age area t has no 
outlet to ! ocean am\nts to ab\t #c p]  
c5t4 ( ! :ole surface4 ,9 o!r c\ntries !
 p]c5tage ( inl& dra9age is mu* l>g]4 ,!
 great ,salt ,lake 9 ,utah is an in/ance
 :]e !re is no outlet = ! wat] except   
?r\gh ! m$ium ( evaporation4 ,inasmu* z 
all riv]s & /reams conta9 a c]ta9       
proportion ( salt1--especially 9 su*    
/rongly alkal9e l& regions z ! ,great   
,bas9 ( ! ,nor? ,am]ican cont95t1--^!   
inl& lakes 9 "t become saturat$ ) ?is & 
o!r m9]al sub/ances4  ,salt is con/antly
 be+ c>ri$ into ! lake by ! wat] ( !    
/ream t fe$s x1 & ! wat] is cont9ually  
be+ evaporat$1 leav+ ! salt beh9d4 ,?is 
process has be5 go+ on 9 ! valley (     
,utah = s long a p]iod t #ag p] c5t4 ( !
 cont5ts ( ! lake is salt4 ,! ,humboldt 
,riv] 9 ,nevada1 :i* empties into a     
small lake ( ! same "n1 & lies at ! foot
 ( ! ,humboldt ,m\nta9s1 is said to h an
 und]gr\nd outlet4 ,?is mu/ be ! case1  
because ! area ( ! lake is v small z    

comp>$ ) ,salt ,lake1 :ile ! riv] t fe$s
 ! latt] is v small comp>$ ) ! "o t fl[s
 into ! =m]4 ,t is to say1 9 ! "o case a
 v small /ream empties into a l>ge lake1
 :ile 9 ! o!r case a mu* l>g] /ream fe$s
 a v small lake4 ,besides1 ,humboldt    
,lake1 unlike ! ,great ,salt ,lake1 is  
said to be a fre%-wat] lake2 if x _h no 
outlet x w\ld become 9 "t saturat$ )    
salt4 ,! l>ge/ body ( wat] 9 ! _w hav+  
no outlet to ! ocean is ! ,caspian ,sea1
 on ! bord] betwe5 ,asia & ,russia 9    
,europe1 x be+ #ahj1jjj squ>e miles 9   
ext5t4  ,:]e riv]s empty into l>ge      
bodies ( wat]1 su* z ! great *a9 ( lakes
 on ! nor!rn bord] ( ! ,unit$ ,/ates 7& 
^! lakes h an outlet connect+ "o ) !    
o!r1 & f9ally by a riv] to ! ocean7 a   
con/ant circulation is be+ kept up1 & ! 
wat] rema9s fre%4 ,ow+ to ! fact1 h[ev]1
 ( ! great evaporat+ surface t ^! lakes 
af=d1 !re is a great] disproportion     
betwe5 ! ra9fall ^u ! dra9age area      
tribut>y to ^! lakes1 & ! am\nt (       
dis*>ge ?r\gh ! ,/4 ,lawr5ce ,riv]1 ?an 

w\ld be ! case ) a riv] t 0 n connect$ )
 a sy/em ( lakes4 ,! am\nt ( ra9fall ^u 
! area dra9$ by ! ,mississippi ,riv]    
dur+ "o ye> am\nts to ab\t #fad cubic   
miles ( wat]1 :ile ! dis*>ge at ! m\? ( 
! ,mississippi ,riv] is only ab\t #aed  
cubic miles4 ,! diff]5ce betwe5 ! two   
figures has be5 c>ri$ up by ! process ( 
evaporation or /or$ 9 vegetation4 ,^!   
figures v>y consid]ably1 h[ev]1 )       
diff]5t ye>s4  ,! proportion ( ra9fall  
to dis*>ge w v>y greatly 9 diff]5t riv]s
 f o!r causes ?an hav+ a l>ge evaporat+ 
surface4 ,?is v>iation is due to !      
diff]5ce 9 ! ability ( ! soil to reta9  
wat] aft] a ra9fall4 ,9 "s dra9age areas
 ! gr\nd is m or less imp]meable to     
wat]1 & 9 ?is case ! wat] runs readily  
(f1 caus+ a sudd5 rise 9 ! riv]2 & z    
sudd5ly x rea*es ! l[-wat] m>k4 ,9 o!r  
dra9age areas ! gr\nd is v p]meable to  
wat]1 s t ! ra9 p5etrates to a great]   
dep? into ! e>?1 :]e x is held1 & by a  
sl[ process dra9s into ! riv]s1 :ile mu*
 m ( x is c>ri$ (f by evaporation & into

 vegetation ?an is ! case 9 ! dra9age   
di/rict be=e m5tion$4  ,! c\rses ( riv]s
 are det]m9$ by ! topography ( ! c\ntry 
?r\gh :i* !y fl[4 ,! s9u\s w9d+s1 t are 
f\nd to be a *>act]i/ic ( ne>ly all     
riv]s1 are caus$ by ! wat]1 ?r\gh ! =ce 
( gravity1 seek+ ! l[e/ level1 & avoid+ 
ob/ructions1 :i* !y c fl[ ar\nd m easily
 ?an remove4  ,great riv]s (t5 *ange _! 
c\rses1 especially :]e !y fl[ ?r\gh a   
region ( made e>?1 su* z is ! case ) !  
l[] ,mississippi ,riv]1 & 9 o!r great   
riv]s ( ! _w4 ,! loose e>? is cont9ually
 %ift$ by ! curr5t1 & :]e ! curr5t is n 
v /rong x w (t5 hold ! wat] back to su* 
an ext5t ( accumulat$ weight t ! flood w
 break ov] at "s weak po9t on its banks 
& make a new c\rse = itself4  ,"o ( !   
great riv]s ( ,*9a--! ,hwangho--(t5     
causes dire de/ruction to life & prop]ty
 ow+ to *ange 9 its b$ f "t to "t4 ,x is
 e/imat$ t betwe5 ! ye>s ( #ahea-ff ?is 
riv] caus$ ! loss ( f #cj1jjj1jjj to    
#dj1jjj1jjj lives ?r\gh dr[n+ & fam9e by
 ! de/ruction ( crops4  ,floods 9 riv]s 

are occasion$ f v>i\s causes4 ,( c\rse !
 prim>y cause is ! same 9 all cases1 t  
is1 f precipitation ( moi/ure 9 ! =m (  
ra9 or sn[4 ,"s riv]s are s relat$ to ! 
area ( ra9fall & to ! p]meability ( !   
soil t !re is b little v>iation 9 !     
am\nt ( dis*>ge ?r\gh\t ! ye>4 ,! great 
riv] ( ,s\? ,am]ica1 ! ,amazon1 is an   
in/ance ( a riv] ( ?is class4 ,a c]ta9  
numb] ( ! small] riv]s t fe$ x lie 9 !  
area ( ra9fall dur+ ! :ole ( ! ye>2 =   
in/ance1 ! /reams ( ! upp] ,amazon are  
be+ f$ by ra9s at "o season ( ! ye>1 :5 
^? fe$+ ! riv] l[] d[n are at ! l[e/    
/age4 ,:5 ! ra9y season prevails 9 !    
upp] section ( ! riv] ! dry season      
prevails f>!r d[n1 :ile at ano!r season 
( ! ye> ^! conditions are rev]s$4       
,!re=e1 ?\gh ! ,amazon has a l>g]       
dra9age bas9 ?an any o!r riv] 9 ! _w1 & 
9 "s p>ts ! ye>ly ra9fall is #bhj in*es1
 !re is no v great fluctuation 9 ! /ages
 ( wat]4 ,! ,or9oco ,riv]1 :i* fl[s     
?r\gh ,v5ezuela1 & ^: dra9age area is   
l>gely cov]$ ) m\nta9s1 has a great]    

fluctuation ?an any o!r riv]1 ! diff]5ce
 betwe5 high & l[ wat] am\nt+ to sev5ty 
feet4  ,! ,riv] ,nile has an annual rise
 ( f f\rte5 to tw5ty-six feet4 ,?is riv]
 is ! sole dep5d5ce ( ! inhabitants (   
l[] ,egypt1 & _! su/5ance dep5ds ^u !   
height to :i* ! riv] rises2 if x does n 
rise high en\gh ! agricultural l&s are n
 suffici5tly irrigat$1 & if x rises too 
high _! crops are de/roy$ by ! floods4  
,9 ?is section !y dep5d entirely ^u !   
ov]fl[ ( ! ,nile = irrigation1 & n ^u ! 
ra9fall4 ,!re is sc>cely ev] a ra9fall 9
 l[] ,egypt except ab\t once a ye> on ! 
coa/ ( ! ,m$it]ranean4 ,aft] asc5d+ !   
riv] = a %ort di/ance we come into an   
area ( no ra9 = a di/ance ( #aejj miles 
along ! riv]4 ,egypt has a sup]ficial   
area ( ab\t #aae1bjj squ>e miles1 & only
 ab\t "o-twelf? ( ?is area is 9 a       
position to be cultivat$4  ,z !re is no 
ra9fall 9 ?is region1 ! sole dep5d5ce = 
agricultural purposes is f ! ,riv] ,nile
 :5 x rises to a suffici5t height to    
admit ( irrigation4 ,! riv] br+s d[n    

quantities ( ri* e>? :i* dur+ ! ov]fl[  
is deposit$1 & ?us ! agricultural       
regions are ref]tiliz$ annually4  ,!    
,riv] ,nile is :at is call$ a tropical  
riv] & is f$ by ! ra9s 9 upp] ,egypt    
caus$ by ! monsoon w9ds t prevail 9 t   
section ( ,africa dur+ ! summ] season1 z
 !y d 9 ,india4 ,z has be5 expla9$ 9 a  
=m] *apt]1 ! monsoon w9ds bl[ /eadily = 
ab\t six mon?s f (f ! s\!rn ocean4 ,^!  
w9ds are highly *>g$ ) moi/ure1 :i* is n
 precipitat$ till x /rikes ! m\nta9\s   
regions ( ! int]ior4 ,"h ! high m\nta9s1
 :i* are (t5 sn[-capp$1 cause a pr(use  
precipitation1 :i* runs (f into ! v>i\s 
fe$]s ( ! ,nile1 caus+ a gradual rise 9 
! riv] t rea*es ! highe/ po9t ab\t      
,septemb] ( ea* ye>4 ,if ! ,nile %\ld   
dry up1 or if ! annual floods %\ld      
mat]ially *ange 9 height1 x w\ld make a 
des]t region ( all t portion ( ,egypt n[
 s productive4  ,! great riv]s ( ,*9a1 !
 ,yang-tse-,kiang & ! ,hwangho1 are also
 tropical riv]s & h an annual flood4    
,sometimes ! rise is z mu* z fifty-six  

feet4 ,^! annual floods are also caus$  
by ! monsoon w9ds t c>ry moi/ure f !    
ocean1 :i* is cond5s$ & precipitat$ 9 ! 
m\nta9s ( c5tral ,asia4 ,! conditions   
are sub/antially ! same z ^? :i* prevail
 at ! s\rces ( ! ,nile 9 ,africa4       
,riv]s are produc$ f all sorts ( causes1
 "s ( !m fl[+ only dur+ ! ra9y season1  
:ile o!rs are f$ by melt+ sn[ f ! high] 
m\nta9s1 & z ! sn[ is r>ely melt$ away  
entirely dur+ ! summ]1 9 ! high m\nta9s1
 !re is a cont9ual fl[ f ?is s\rce4 ,!  
sn[ =ms a sy/em ( /orage1 s t ! wat] is 
held back & is gradually giv5 up z x    
melts4 ,if ?is 7 n true m\nta9\s regions
 w\ld be subject$ to disa/r\s floods4   
,if ! precipitation 7 always 9 ! =m (   
ra9 x w\ld imm$iately run (f in/ead (   
be+ di/ribut$ ov] a :ole season4 ,!     
,platte is an in/ance ( a riv] l>gely f$
 by ! melt+ sn[s--( ! ,rocky ,m\nta9s4  
,9 ! region ( glaci]s 9 ! m\nta9s (     
,alaska & ,switz]l& riv]s are f$ by !   
melt+ ice4 ,^! riv]s are usually ( a    
milky color occasion$ by ! pulv]ization 

( rock caus$ by ! gr9d+ ( ! great       
glaci]s z !y fl[ d[n ! gul*es 9 ! m\nta9
 side4 ,9 "s regions ^! glacial riv]s h 
a diurnal v>iation4 ,?is is caus$ by !  
fact t ! glaci] is s situat$ t x freezes
 at night1 :i* *ecks ! fl[1 & ?aws 9 !  
daytime1 :i* increases x4  ,riv]s are to
 ! globe :at ! ve9s are to ! animal     
organization4 ,!y pick up ! surplus     
moi/ure n ne$$ 9 ! gr[? ( vegetation & =
 ! su/5ance ( animal life1 & c>ry x on1 
toge!r ) ! debris t x ga!rs 9 its c\rse1
 to ! great res]voirs1 ! seas & oceans1 
:]e x is r$i/ill$ & purifi$ by ! action 
( ! sun's rays4 ,f "h x is c>ri$ back 9 
! =m ( invisible moi/ure & aga9         
precipitat$ 9 ! purifi$ /ate1 to help   
c>ry on ! great op]ations ( gr[?--animal
 & vegetable4 ,! vaporiz$ moi/ure t is  
c>ri$ back by ! w9ds & r$i/ribut$       
corresponds to ! blood1 aft] x has be5  
purifi$ & is c>ri$ back ?r\gh ! art]ies 
to ! extremities & capill>y vessels :i* 
fe$ & n\ri% ! bodily organs4     ,,*apt]
 ,,xx4  ,,tides4   ,anyone :o has sp5t a

 summ] at ! sea%ore has obs]v$ t ! wat] 
level ( ! ocean *anges twice 9 ab\t     
tw5ty-f\r h\rs1 or p]haps x w\ld be a   
bett] /atem5t to say t x is cont9ually  
*ang+ & t twice 9 tw5ty-f\r h\rs !re is 
a po9t :5 x rea*es its highe/ level &   
ano!r :5 x rea*es its l[e/4 ,x sw+s back
 & =? l a p5dulum1 mak+ a complete      
oscillation once 9 twelve h\rs4 ,:5 we  
come to /udy ?is ph5om5on closely we f9d
 t x v>ies ea* day1 & t = a c]ta9 p]iod 
( "t ! wat] w rea* a high] level ea*    
succe$+ day until x culm9ates 9 a       
maximum height1 :5 x beg9s to gradually 
dim9i% f day to day until x has rea*$ a 
m9imum4 ,"h x turns & goes ov] ! same   
r\nd aga94 ,x w be fur!r obs]v$ t ! "t  
occupi$ betwe5 "o high tide & ! next "o 
is a trifle ov] twelve h\rs4 ,t is to   
say1 ! two ebbs & fl[s t occur ea* day  
require a little m ?an tw5ty-f\r h\rs1 s
 t ! tidal day is a little long] ?an !  
sol> day4 ,x corresponds to :at we call 
! lun> day4  ,z all "k1 ! moon goes     
?r\gh all its phases once 9 tw5ty-eight 

days4 ,! tide consid]$ 9 its simple/    
aspect is a /ruggle on ! "p ( ! wat] to 
foll[ ! moon4 ,!re is a mutual          
attraction ( gravitation betwe5 ! e>? & 
! moon4 ,because ! wat] ( ! e>? is      
mobile x t5ds to pile up at a po9t ne>e/
 ! moon4 ,b ! e>? z a :ole also moves   
t[>d ! moon1 & m ?an ! wat] does1 keep+ 
its r\nd %ape1 :ile its movable wat]    
7practically envelop+ x7 is pil$ up be=e
 x t[>d ! moon & left accumulat$ beh9d x
 away f ! moon4 ,s t 9 a r\gh way x is a
 solid s\nd e>?1 surr\nd$ by an oval    
body ( wat]3 ! long axis ( ! oval       
repres5t+ ! high tides1 :i*1 z !y foll[ 
! moon1 slide completely ar\nd ! e>?    
once 9 e tw5ty-f\r h\rs4 ,?us1 !re are  
really two high tides & two l[ tides    
mov+ ar\nd ! e>? at ! same "t2 & ?is    
acc\nts = ! two daily tides4  ,we h     
acc\nt$ = ! "t :5 !y occur 9 ! fact t ! 
wat] attempts to foll[ ! moon1 b ?is    
does n acc\nt = ! gradual *anges 9 !    
am\nt ( fluctuation f day to day4 ,!    
problem is complicat$ by ! fact t ! sun 

also has an attraction = ! e>? z well z 
! moon4 ,b f ! fact t ! sun is some?+ l 
#djj times fur!r f ! e>? ?an ! moon is1 
& also ! fact t ! attraction ( "o body =
 ano!r v>ies inv]sely z ! squ>e ( !     
di/ance1 ! moon has an imm5se advantage 
ov] ! sun1 al?\gh s mu* small]4 ,if !   
p[] ( ! moon 7 entirely susp5d$1 or if !
 moon 7 blott$ out ( exi/5ce1 !re w\ld  
/ill be a tide4 ,! fluctuation betwe5   
high & l[ tide w\ld n be ne>ly s great z
 x is at pres5t1 b x w\ld occur at !    
same "t ea* day1 because x w\ld be :olly
 a product ( ! sun4  ,x w be easily se5 
t ^! two =ces act+ ^u ! wat] at ! same  
"t w cause a complicat$ condition 9 !   
movem5t ( ! wat]s ( ! ocean4 ,!re w come
 a "t once 9 tw5ty-eight days :5 ! sun &
 ! moon w act conjo9tly1 & bo? w pull 9 
! same direction at ! same "t ^u ! wat]4
 ,?is jo9t action ( ! sun & moon        
produces ! highe/ tide1 :i* is call$ !  
spr+ tide4 ,f ?is po9t1 h[ev]1 ! tides w
 gr[ less ea* day1 because ! relation ( 
! sun & moon is con/antly *ang+1 ow+ to 

! fact t x requires #cfe days = ! sun to
 complete 8 app>5t revolution ar\nd !   
e>?1 :ile ! moon does h] actual c\rse 9 
tw5ty-eight days4 ,:5 ! sun & moon h    
*ang$ _! relative positions s t !y are  
at "r angles to ea* o!r ) ref]5ce to !  
e>?--at a qu>t]-circle ap>t--! sun &    
moon w be pull+ aga9/ ea* o!r2 at lea/  
?is is ! po9t :]e ! moon is at ! greate/
 disadvantage ) ref]5ce to its ability  
to attract ! wat]4  ,because "o-qu>t]   
ar\nd ! e>? ! sun is creat+ 8 own tide1 
:i* to t ext5t c\nt]acts ! effect       
produc$ by ! moon1 ! tide "u ! moon at  
?is po9t is at its l[e/ po9t & is call$ 
! neap tide4 ,:5 ! moon has pass$ on    
ar\nd ! e>? to a po9t :]e x is opposite 
to t ( ! sun--at a half-circle ap>t--!re
 w be ano!r spr+ tide1 & !n ano!r neap  
tide :5 x is on ! la/ qu>t]1 & f t po9t 
! tide w increase daily until x rea*es !
 po9t :]e ! sun & moon are 9 exact l9e )
 ref]5ce to ! e>?'s c5t]1 :5 ano!r spr+ 
tide occurs4 ,f ?is x w be se5 t !re are
 two spr+ tides & two neap tides 9 ea*  

tw5ty-eight days4 ,?is is ! fundam5tal  
law gov]n+ tides4  ,!re are _m o!r      
conditions t modify tidal effects4      
,nei!r ! sun nor ! moon is always at !  
same di/ance f ! e>?4 ,s t !re w be a   
v>iation at times 9 high & l[ tides4 ,= 
in/ance1 x w happ5 sometimes t :5 bo? ! 
sun & moon are act+ conjo9tly !y w bo?  
be at _! ne>e/ po9t to ! e>?1 & :5 ?is  
is ! case ! spr+ tide w be mu* high] ?an
 usual4  ,= _m ye>s ! writ] has obs]v$ t
 artesian wells1 made by deep bor+s (   
small diamet] into ! e>? to a wat]      
supply1 h a daily p]iod ( ebb & fl[1 z  
well z a neap & spr+ tide1 ! same z !   
tides ( ! ocean1 except t ! process is  
rev]s$4 ,! "t ( greate/ fl[ ( an        
artesian well w occur at l[ tide 9 !    
ocean4 ,?is might be acc\nt$ = f ! fact 
t :5 ! tide is at its height ! moon is  
also pull+ ^u ! cru/ ( ! e>?1 :i* w\ld  
t5d to take ! pressure (f ! s& rock :i* 
lies "o or two ?\s& feet bel[ ! surface 
& ?r\gh :i* ! fl[ ( wat] comes1 & ?us   
slack5 ! fl[4 ,:5 ! moon is 9 position =

 l[ tide1 ! cru/ ( ! e>? w\ld settle    
back & ?us produce a great] pressure ^u 
! wat]-be>+ rock4 ,?is is ! only !ory t 
has sugge/$ itself to ! writ] t w\ld    
seem to acc\nt = ^! ph5om5a4  ,look$ at 
f "o /&po9t1 x is easy to acc\nt = tidal
 action4 ,b :5 we attempt to make up a  
table giv+ ! h\r & m9ute z well z !     
height ( ! tide at t p>ticul> "t we f9d 
t we h a v complicat$ ma!matical        
problem4 ,h[ev]1 tables are made out s t
 we "k at j :at "t 9 ! day a tide w     
occur e day 9 ! ye>4     ,,*apt] ,,xxi4 
,,:at ,,is ,a ,,sponge8   ,be=e ent]+ ^u
 ! great subject ( wat] & ice--two ( !  
mo/ trem5d\s factors 9 _w-build+--let u 
consid] a small matt]1 s f> z its       
p]man5t effects are conc]n$1 yet "o :i* 
ent]s l>gely into ! com=t & heal? (     
mank9d1 & :i*1 ?\gh an animal1 may be   
discuss$ :]e x belongs--"u ,wat]4  ,!re 
are few ?+s m famili> ab\t ! ord9>y     
h\sehold ?an a piece ( sponge1 & yet1   
p]haps1 !re are b few ?+s ab\t :i* !re  
is s little kn[n4 ,! sponge _h be5 9 use

 _m1 _m ye>s be=e x 0 giv5 a place 9    
ei!r ! animal or vegetable k+dom4 ,!    
casual obs]v]1 because he saw x atta*$  
to a rock1 jump$ to ! conclusion t x 0 (
 vegetable orig94 ,b aft] be+ kick$ back
 & =?1 s to speak1 f "o k+dom to ! o!r1 
ev5 by :at are call$ well-educat$ p1 x  
has f9ally be5 receiv$ into ! family (  
animals2 a dignity 9 :i* ! sponge itself
 seems to take b little int]e/4  ,!     
sponge is f\nd 9 ! bottom ( ! sea2 at no
 v great dep?1 h[ev]4 ,x is usually     
atta*$ to a rock or "s o!r sub/ance & x 
is due to ?is fact *iefly t x has be5   
class$ z a vegetable4 ,at lea/ "o       
sci5ti/ has attempt$ to give x a place  
betwe5 ! two k+doms1 b ?is only adds    
confusion )\t giv+ any satisfactory     
explanation ( its orig94 ,x seems to    
belong to a v l[ ord] ( animal life4 ,x 
brea!s wat] in/ead ( air1 b probably1 l 
_m o!r wat] animals1 x absorbs ! oxyg5 f
 ! air :i* is m or less conta9$ 9 !     
wat]4 ,!re is a process ( oxidation go+ 
on )9 ! sponge 9 a mann] some:at z we   

f9d x 9 ord9>y animal life1 & l ! animal
 x expels c>bon dioxide4 ,all ?is1      
h[ev]1 is c>ri$ on app>5tly )\t any     
lungs or any dige/ive organs1 or 9 fact 
any ( ! organs t are common to ! animals
 ( ! high] ord]4 ,! sponge1 h[ev]1 z we 
see x 9 our ba?rooms1 is only !         
framework1 bony /ructure1 or skeleton ( 
! animal4  ,! sponge is exce$+ly por\s &
 readily absorbs wat] or any fluid by ! 
well-kn[n process ( capill>y attraction4
 ,! sponge fib] is v t\gh & is n l any?+
 kn[n to exi/ 9 ! vegetable k+dom4 ,!   
sub/ance analyzes almo/ ! same z ord9>y 
silk1 :i* all "k is an animal product4  
,if we burn a piece ( sponge x exhibits 
v mu* ! same ph5om5a z ! burn+ ( hair or
 wool1 & ! smell is v mu* ! same4  ,!   
/ructure ( a piece ( sponge :5 exam9$ "u
 a microscope is a wond]fully complicat$
 fabric4 ,"u ! microscope x %[s a       
network ( int]lac+ filam5ts runn+ 9 e   
direction 9 a sy/em ( curv$ l9es        
int]sect+ & int]lac+ ) ea* o!r 9 a mann]
 to leave capill>y op5+s4  ,x is a      

wond]ful /ructure1 & "o t a me*anical   
eng9e] c\ld get _m valuable lessons f4  
,x w /& a /ra9 9 "o direction z well z  
ano!r4 ,!re are no special lam9ations or
 l9es ( cleavage2 x is v resili5t or    
ela/ic1 & readily yields to pressure1 b 
z readily comes back to its normal      
position :5 ! pressure is reliev$4 ,if  
we exam9e ! body ( a sponge we %all     
notice t !re are occasional l>ge op5+s  
into x1 b ev]y:]e surr\nd$ by small]    
ones4 ,if we %\ld capture a live sponge 
& place x 9 an aqu>ium ) sea wat]1 :]e  
we c\ld /udy x1 we %\ld f9d a           
circulation con/antly go+ on1 & t wat] 0
 con/antly suck$ 9 at ! small] op5+s all
 ov] ! outside ( ! sponge & z cont9u\sly
 eject$ f ! l>ge op5+s4 ,?is process    
con/itutes :at corresponds 9 ! high]    
ord] ( animals to bo? respiration &     
blood circulation1 comb9$4 ,! sponge    
fe$s ^u sub/ances t are ga!r$ up f ! sea
 wat]1 & brea!s ! air conta9$ 9 ! same1 
s t x brea!s1 eats1 & dr9ks ?r\gh ! same
 set ( organs4  ,:5 we fir/ capture a   

live sponge f ! sea x has a slimy1 dirty
 appe>ance1 & is v heavy4 ,! sponge is  
f\nd to be fill$ ) a glut9\s sub/ance t 
is ! fle%y "p ( ! animal4 ,x is v s(t & 
jelly-l1 & aft] ! sponge is dead x is   
readily squeez$ out1 by a process :i* is
 call$ tak+ ! milk out1 :i* leaves      
simply ! skeleton1 ! only useful "p z an
 article ( comm]ce4 ,?is fle%y sub/ance1
 9 life1 has some:at ! appe>ance &      
composition ( ! :ite ( an egg4  ,!      
me*anical process by :i* ! sponge takes 
its n\ri%m5t is exce$+ly int]e/+4 ,!re  
are small globe-%ap$ cells ) op5+s ?r\gh
 !m t are l9$ ) little hairlike         
projections t move 9 su* a mann] z to   
suck ! wat] 9 at "o side ( ! cell & pu% 
x out at ! o!r4 ,^! little fib]s are    
te*nically call$ cilia4 ,we might       
describe !m z little suction pumps t are
 locat$ at _m po9ts 9 ! sponge1 all act+
 conjo9tly to produce a circulation     
?r\gh ! f9] op5+s or capill>y vessels & 
f9ally dis*>g+ into ! l>g] *amb]s :i*   
c>ry (f ! residue4 ,if we %\ld analyze !

 wat] z x is suck$ into ! sponge & t :i*
 issues f x ?r\gh ! l>g] op5+s1 we %\ld 
f9d a diff]5ce betwe5 ! two4 ,! expell$ 
wat] w\ld conta9 m or less c>bon        
dioxide4  ,!re are _m diff]5t v>ieties (
 sponge1 &1 :ile !y all possess c]ta9   
*>act]i/ics 9 common1 !y are /ill v     
diff]5t 9 _m respects4 ,"s ( !m are l>ge
 & co>se1 :ile o!rs are exce$+ly s(t &  
velvety4 ,:at is call$ a s+le sponge is 
a colony ( animals r ?an a s+le animal2 
at lea/ !y are s reg>d$ by zooelogi/s4  
,?is c h>dly be true if we reg>d !      
sponge itself z a "p ( ! animal4 ,if !  
sponge is simply reg>d$ z ! h\se 9 :i* !
 animal lives !n x becomes a great      
t5em5t ) num]\s occupants4 ,b x is a    
t5em5t ^u :i* ! life ( ! sponge dep5ds1 
& is a "p ( x4  ,! sponge c\ld n brea!  
)\t ! fibr\s /ructure 9 ! cells conta9+ 
! ma*9]y = produc+ ! circulation4 ,x w  
be se5 t ! sponge1 :ile x is an animal1 
is ( ! v simple/ v>iety1 s f> z its     
organs are conc]n$4 ,true1 its framework
 is v complicat$1 b ! organs = su/a9+ ! 

life ( ! animal are ! simple/ possible4 
,! little self-act+ pumps pull ! wat]   
into ! sponge ?r\gh ! small] op5+s1 :]e 
x appropriates ! food sub/ance f ! wat] 
& :]e a *emical action takes place :i*  
builds up ! fle%y sub/ance ( ! animal1 &
 !n expels ! residue :i* is n ne$$ to   
support its life4  ,simple z x is1      
h[ev]1 z a me*anical /ructure1 ! life & 
gr[? ( ! sponge is z my/]i\s z t ( ! mo/
 highly organiz$ animal or ev5 ! s\l (  
man4 ,we c /udy out ! /ructure ( a plant
 or animal2 we c analyze x & tell :at   
are ! elem5ts ( :i* x is compos$2 we c  
describe ! me*anical op]ations t are    
c>ri$ on & ! *emical comb9ations t take 
place1 b no man has ev] yet solv$ !     
my/]y ( life1 ev5 9 ! l[e/ =m--:e!r     
animal or vegetable4  ,! sponge1 :e!r   
consid]$ z a s+le or comp\nd animal1 has
 ! p[] to reproduce itself1 & "h ! my/]y
 ( life is z mu* hidd5 z x is 9 ,god's  
highe/ creation4 ,x has be5 /at$ t e    
sponge conta9s a l>ge numb] ( sep>ate   
cells :i* c>ry on ! op]ation (          

circulation & respiration1 & may be     
lik5$ to ! he>t & lungs ( an animal ( a 
high] creation4 ,zooelogi/s claim t ea* 
"o ( ^! cells repres5ts a sep>ate       
animal1 liv+ 9 a common /ructure4 ,h[ev]
 ?is may be1 x is an int]e/+ fact t !   
sponge has ! p[] ( secret+ ova t gr[ 9  
l>ge numb]s 9 little sacks until !y h   
rea*$ a c]ta9 /age ( progress1 :5 !y are
 expell$ f ! "m sponge & turn$ adrift 9 
! great ocean to /ruggle = _! own       
exi/5ce4 ,^! eggs d n diff] mu* 9 _!    
/ructure & composition f an ord9>y h5's 
egg1 except t !re is no %ell1 only a sk9
 provid$ ) little fib]s call$ cilia1 t  
project f x1 & by ! movem5t ( ^! !      
embryo sponge is able to propel itself  
?r\gh ! wat]4 ,x ?us lives until x has  
rea*$ a c]ta9 /age ( developm5t1 :5 x   
seeks out a pebble or rock1 to :i* x    
atta*es itself at "o end--prep>ation =  
:i* has be5 made by its peculi> /ructure
 dur+ its life :5 x 0 free to float     
ar\nd ?r\gh ! wat]4 ,x is n[ a prison] &
 *a9$ to ! rock x has select$ = !       

f\ndation ( its home4 ,hav+ no long] any
 use = ! little cilia1 :i* enabl$ x to  
swim ?r\gh ! wat]1 x n[ loses !m4 ,"h is
 a beautiful illu/ration ( h[ nature    
provides = ! necessities ( ! smalle/    
?+s1 & h[ :5 ! necessity t dem&$ a c]ta9
 condition passes by ! condition passes 
) x4 ,! embryo beg9s to %[ a fibr\s     
developm5t1 :i* is ! beg9n+ ( !         
framework ( a new sponge4 ,evolution    
goes on1 e /ep ( :i* is z my/]i\s z a   
miracle1 until ! gr[+ ?+ is a full-gr[n 
sponge1 equipp$ ) ! means = respiration1
 circulation1 fe$+1 dige/ion1 &         
reproduction4  ,sponges gr[ 9 ! bottom (
 ! sea at diff]5t dep?s4 ,!y are obta9$ 
by div]s :o make a bus9ess ( ga!r+ !m4  
,! be/ sponges are call$ ! ,turki%      
sponge1 :i* are v s(t & velvety1 & may  
be blea*$ until !y are ne>ly :ite by    
subject+ !m to ! action ( c]ta9 acids4  
,! div]s become v exp]t1 b !y d n h !   
mod]n equipm5ts ( a div+ suit4 ,!       
,syrian div]s 9 ! ,m$it]ranean g d[n    
nak$ ) a rope atta*$ to _! wai/s & a    

/one atta*$ to ! rope to cause !m to    
s9k1 toge!r ) a bag = c>ry+ ! sponges4  
,!y h tra9$ !mselves until !y c rema9 "u
 wat] f a m9ute to a m9ute & a half1 & 9
 t "t c ga!r f "o to ?ree doz5 sponges4 
,! ord9>y dep? to :i* !y desc5d is f    
eight to twelve fa?oms4 ,b a v exp]t    
div] w g d[n z f> z =ty fa?oms4 ,! bett]
 class ( sponges are said to gr[ 9 !    
deep] wat]s4 ,! co>se inf]ior sponges   
are call$ ! ,bahama sponge4 ,?is sponge 
is ( a peculi> %ape1 gr[+ m l a bru%1 ) 
long bri/ly fib]4  ,! trade 9 sponges is
 q l>ge4 ,! consumption 9 ,great ,brita9
 alone am\nts to ab\t #a1jjj1jjj p]     
annum4  ,! sponge z an animal possesses 
_m advantages ov] 8 m ari/ocratic       
neighbor1 man4 ,he brea!s b he has no   
lungs1 & !re=e _c h pneumonia4 ,he      
dige/s 8 food1 b he has no /oma*1 &     
!re=e nev] has dyspepsia1 ga/ritis1 or  
any ( ! _m ailm5ts t belong to t mu*    
abus$ organ4 ,he has no inte/9es1 &     
!re=e _c h app5dicitis or ,asiatic *ol]a
 or any ( ! long tra9 ( diseases incid5t

 to ^? complicat$ organs4 ,he has no    
n]v\s sy/em--oh1 happy sponge6--!re=e he
 _c h n]v\s pro/ration1 hy/]ia1 or      
epilepsy4 ,he has no use = doctors1 &   
!re=e has no unpleasant discussions ) 8 
neighbors ab\t ! relative m]its ( !     
diff]5t s*ools ( m$ic9e4 ,if he has any 
pr$ilections 9 ! way ( pa?ies we %\ld   
say t he is a hydropa?4 ,:ile he is a   
great dr9k]1 he is n at all             
convivial--he dr9ks only wat]1 & takes t
 9 solit>y sil5ce4 ,he s[s all 8 wild   
oats :5 he is v "y1 :ile he has ! fre$om
 to roam at w4 ,he soon tires ( ?is1    
h[ev]1 = he selects ! rock t is to be ! 
f\ndation ( 8 future home & !re settles 
d[n = life1 wrapt 9 ! solitude ( 8 own  
orig9ality4 ,he is n tr\bl$ ) w>s or    
rumors ( w>s4 ,8 eyes are nev] />tl$ or 
8 n]ves %ak5 by ! sc>e headl9es ( yell[ 
j\rnalism4 ,! "o s5sation ( 8 life1 if  
s5sation he ev] has1 is :5 a great ugly 
creature ( "s ,ori5tal clime comes d[n  
to 8 home & te>s him away f 8 native    
rock1 c>ries him to ! surface1 & !re    

lit]ally squeezes ! life out ( him4 ,he 
f9ally dies ( ! grip1 & "h he s9ks to ! 
level ( 8 m ari/ocratic neighbor4  ,b   
!re is ano!r side to our philosophy4 ,if
 ! sponge is exempt f all ^! ills t we h
 enum]at$ x is because he is incapable (
 suff]+ & is !re=e incapable ( enjoym5t4
 ,^? be+s t h ! ability to suff] mo/ h  
also ! ability to enjoy mo/4 ,! high] ! 
type ( civilization ! great]            
possibilities x (f]s = real             
enjoym5t--also = real mis]y4 ,?is be+   
true1 x %\ld be ! aim ( highly civiliz$ 
p to elim9ate z f> z possible ^? ?+s t  
make = mis]y1 & cultivate ^? ?+s t make 
= happ9ess 9 ! highe/ & be/ s5se4       
,,*apt] ,,xxii4  ,,wat] ,,& ,,ice4   ,we
 n[ h ent]$ ^u a subject t is ( int5se  
int]e/1 /udi$ f ! /&po9t ( facts z !y   
exi/ to-day & ( hi/ory z we read x 9 !  
rocks & b[ld]s t we f9d di/ribut$ ov] ! 
face ( ! e>?4  ,! :ole nor!rn "p ( !    
,unit$ ,/ates ext5d+ to a po9t s\? (    
,c9c9nati 0 at "o "t cov]$ ) a great    
ice-%eet1 traces ( :i* are pla9ly       

visible to anyone :o has made any?+ ( a 
/udy ( ?is subject4 ,! glaci]s n[ to be 
se5 9 ,briti% ,columbia & ,alaska1 great
 z !y seem to "o view+ !m to-day1 are by
 comp>ison ) :at once exi/$ simply      
microscopic specks ( ice4 ,glaci]s1 l   
riv]s1 fl[ by gravity1 foll[+ ! l[e/ b$ 
& l9es ( lea/ resi/ance2 ! diff]5ce be+ 
t 9 ! "o case ! fl[ is rapid1 :ile 9 !  
o!r x is sc>cely visible1 except by     
measurem5t f day to day4 ,be=e ent]+ ^u 
a description ( ! law t gov]ns ! fl[ (  
glaci]s1 let u /op & give a little /udy 
to ! ph5om5a ( wat] z exhibit$ :5 x is  
at ! freez+ po9t4 ,wat] is su* a l>ge   
factor 9 ! make-up ( our globe & ! air t
 surr\nds x t x becomes a v int]e/+ &   
important /udy to anyone :o wi%es to    
und]/& ! ph5om5a ( nature t are closely 
relat$ to x4  ,z all "k1 pure wat] is a 
comp\nd ( two gases1 oxyg5 & hydrog51   
comb9$ 9 ! proportion ( two atoms (     
hydrog5 & "o ( oxyg54  ,let u n[ /udy   
?is fluid 9 its relation to heat4 ,!    
read] is ref]r$ to ! *apt]s on heat 9   

,vol4 ,,ii41 :]e x is /at$ t heat is a  
mode ( motion4 ,x is also /at$ t heat is
 a =m ( en]gy1 & t en]gy is             
inde/ructible1 t an unv>y+ am\nt ( x    
exi/s 9 "s =m or ano!r ?r\gh\t !        
univ]se4 ,x is n always manife/$ z heat 
or electricity1 al?\gh bo? ( ^! are     
always 9 evid5ce z active ag5ts ( =ce4  
,mu* ( ! en]gy is simply /or$--all ! "t 
possess+ ! ability to d "w or to be     
conv]t$ into any ( its kn[n =ms1 su* z  
heat1 light1 electricity1 or me*anical  
motion4 ,a weight t is w\nd up has      
requir$ a c]ta9 am\nt ( en]gy to elevate
 x to ! position t x occupies4 ,:ile 9  
its elevat$ position x possesses en]gy1 
al?\gh n active4 ,en]gy 9 ?is =m is     
call$ pot5tial 7possible7 en]gy1 & has !
 p[] to d "w if releas$4 ,active en]gy  
is call$ k9etic 7mov+7 en]gy1 & ! sum ( 
^! two en]gies is a con/ant quantity4   
,we w n[ /udy en]gy z x is relat$ to    
wat] 9 ! =m ( heat4 ,!re is a k9d ( heat
 call$ lat5t heat1 :i* is n heat at all1
 b /or$ en]gy1 wait+ to be turn$ into   

heat1 or light1 or "s o!r active =m4    
,prop]ly speak+1 heat is a movem5t ( !  
atoms ( matt]1 ! int5sity ( :i* is      
measurable 9 degrees1 & call$ its       
temp]ature4 ,to use ! t]m lat5t heat z  
mean+ conceal$ heat1 :i* mu/ reappe> z  
heat1 is a misnom] & is v mislead+4 ,if 
x is prop] to call a w\nd-up spr+ or    
weight lat5t heat !n its pres5t use is a
 correct "o4 ,:at 0 =m]ly t]m$ lat5t    
heat is simply a =m ( pot5tial en]gy4   
,:5 s5sible heat t is measurable1 z     
temp]ature1 disappe>s 9 ! p]=mance ( "s 
sort ( "w1 especially 9 connection )    
c]ta9 ph5om5a relat+ to wat]1 we call   
x--or r miscall x--lat5t heat3 b !      
phrase w\ld bett] be /or$ en]gy4  ,!    
action ( wat] "u heat is v peculi>1 & 9 
ord] to get a correct und]/&+ ( !       
ph5om5a exhibit$ 9 glacial action we    
also ne$ to und]/& ! ph5om5a ( wat] at !
 freez+ po9t4 ,z is well kn[n1 fre% wat]
 freezes at #cb degrees ,fahr5heit1 & at
 ! mom5t ( freez+ !re is a sudd5        
expansion to su* an ext5t t a cubic foot

 ( ice w occupy a mu* l>g] space ?an x w
 9 ! =m ( wat]2 & because x occupies s  
mu* l>g] space x is light] ?an ! same   
bulk ( wat] w\ld be1 & !re=e x floats 9 
wat]4  ,at ! po9t ( freez+1 ! !rmomet]  
if plac$ on ! ice w regi/] #cb degrees4 
,if ! ice is all[$ to melt1 ! wat] at ! 
mom5t ( liquefaction w\ld be f\nd to    
regi/] ! same degree ( temp]ature z !   
ice :5 fir/ froz54 ,& yet !re has be5 a 
va/ exp5diture ( en]gy betwe5 ! po9ts ( 
liquefaction & congelation1 not)/&+ !   
temp]ature ( ice may be l[]$1 aft] x is 
=m$1 _m degrees1 :i* is measurable by ! 
!rmomet]4 ,suppose we take a piece ( ice
 :i* is #aj degrees bel[ ! freez+ po9t &
 ins]t 9 x a !rmomet]4 ,if n[ we apply  
heat to ?is ice ! !rmomet] w gradually  
rise until x rea*es ! melt+ po9t at #cb 
degrees ,fahr5heit1 :]e x w /& until all
 ! ice is melt$4 ,! application ( heat  
is go+ on /eadily1 b !re are no         
indications ( movem5t 9 ! m]cury until !
 la/ trace ( ice ) :i* x is 9 contact   
has be5 liquefi$4 ,aft] ! ice is all    

melt$1 if ! application ( heat to ! body
 ( liquefi$ ice be cont9u$1 ! column (  
m]cury w resume its movem5t upw>d until 
x rea*es ! boil+ po9t1 :]e x is aga9    
arre/$4 ,& no matt] h[ mu* heat is      
appli$ to ! boil+ wat]1 if 9 an op5     
vessel1 ! !rmomet] rema9s ! same until  
all ! wat] is evaporat$4 ,"h are two    
curi\s facts1 & !y are facts t1 if we c 
ma/] !m1 w s]ve z a key to ! und]/&+ (  
mu* t is my/]i\s 9 nature4  ,x w be our 
endeavor to give ! read] a m5tal picture
 ( :at is tak+ place dur+ ! "t ! ice is 
melt+ & ! !rmomet] is /ation>y4 ,d n    
suppose t y c und]/& ?is1 ev5 s f> z x  
is und]/&able1 by a casual read+ )\t    
?\ght4 ,no man 0 ev] yet able to pres5t 
a picture to ! m9d ( ano!r1 h[ev] cle>ly
 & simply x may be done1 unless t o!r   
m9d is receptive4 ,:5 a photograph]     
tra9s 8 cam]a ^u an object1 h[ev] int5se
 ! light may be & h[ev] clean-cut !     
picture t is ?r[n ^u ! plate 9 ! cam]a1 
unless t plate is prop]ly s5sitiz$ s t !
 picture may be impress$ ^u x1 all ( !  

o!r conditions are 9 va94 ,! read] is   
always a "p ( ! book he is read+4       
,,*apt] ,,xxiii4  ,,/or$ ,,en]gy ,,9    
,,wat]4   ,9 our la/ *apt] we trac$ !   
upw>d movem5t 9 ! m]cury ( ! !rmomet] f 
#aj degrees bel[ ! freez+ po9t up to !  
boil+ po9t ( wat]4 ,we f\nd t ! !rmomet]
 0 arre/$ at #cb degrees & rema9$       
/ation>y at t po9t until all ! ice 0    
melt$1 not)/&+ ! fact t heat 0 be+      
con/antly appli$4 ,aft] ! ice is all    
melt$ ! m]cury moves upw>d until x      
rea*es ! boil+ po9t ( wat]1 :]e !       
movem5t is aga9 arre/$1 & al?\gh ! heat 
is be+ cont9u\sly appli$1 x rema9s      
/ation>y until all ! wat] is evaporat$4 
,if we pu% ! process /ill fur!r1 ) a    
suffici5t application ( en]gy we c      
sep>ate ! vapor molecules into _!       
orig9al elem5ts1 oxyg5 & hydrog54  ,let 
u g back n[ to ! freez+ po9t ( wat] &   
see :at is becom+ ( ! heat t is consum$ 
9 melt+ ! cake ( ice1 & /ill does n     
produce any effect ^u ! m]cury 9 !      
!rmomet]4 ,s5sible heat1 z be=e /at$1 is

 a movem5t ( ! atoms ( matt]1 &         
temp]ature1 z x affects ! !rmomet]1 is a
 measure ( ! int5sity ( motion exhibit$ 
by ^! atoms4  ,9 ! exp]im5t ( ! block ( 
ice t 9 ! beg9n+ is #aj degrees bel[ !  
freez+ po9t1 z %[n by ! !rmomet]1 !     
molecules h a def9ite int5sity ( motion4
 ,! int5sity ( ?is motion increases :5  
heat is appli$ until x rea*es #cb       
degrees1 :5 x rema9s /ation>y until all 
( ! ice is melt$4 ,at ?is po9t !re is a 
re>rangem5t ( ! molecules ( wat] z x    
assumes ! liquid /ate4 ,to p]=m ?is     
re>rangem5t requires a c]ta9 am\nt ( "w 
done1 :i* is analog\s to ! w9d+ up ( a  
weight to a c]ta9 di/ance4 ,!re has be5 
en]gy us$ 9 w9d+ up ! weight1 b t en]gy 
n[ is n de/roy$1 nor /ill 9 ! =m ( heat1
 b is 9 ! pot5tial /ate--ready to d "s  
o!r k9d ( "w4 ,s1 ! heat t has be5      
appli$ to ! melt+ ice has be5 utiliz$   
dur+ ! process ( its liquefaction 9     
re>rang+ ! wat] molecules & putt+ !m 9 a
 /ate ( /ra91 s to speak1 l ! weight t  
is w\nd up to a c]ta9 height4 ,!re is a 

c]ta9 am\nt ( pot5tial en]gy t is /or$ 9
 ! molecules ( wat] t w be giv5 up &    
become active en]gy 9 ! =m ( heat1 if ! 
wat] is aga9 froz54 ,to melt a cubic    
foot ( ice requires z mu* heat z x w\ld 
to raise a cubic foot ( wat] #add       
degrees ,fahr5heit4 ,b1 z we h se51 :ile
 all ( ?is en]gy is absorb$ z heat1 x is
 n lo/ z en]gy4 ,x ceases to be k9etic  
or active & becomes pot5tial en]gy4 ,?is
 7let u repeat7 has be5 call$ lat5t     
heat4 ,! t]m grew out ( ! old idea t    
heat 0 a fluid & t :5 x became lat5t x  
hid itself away some:]e 9 ! int]atomic  
spaces ( matt] & ceas$ to be long]      
s5sible heat4 ,x came into exi/5ce 9 !  
same mann] & occupies ! same place 9 !  
sci5ce ( heat t ! ^w curr5t does 9 !    
sci5ce ( electricity3 bo? ( !m are      
misnom]s4  ,:5 ! ice is all melt$       
pot5tial en]gy is no long] /or$1 b is   
manife/$ 9 ! s5sible heat+ ( wat]1 !    
degree ( :i* is measurable by !         
!rmomet]1 until x rea*es ! boil+ po9t1  
:]e x is aga9 arre/$4 ,all ( ! surplus  

heat above t temp]ature is consum$ 9    
r5d+ ! liquid wat] into moi/ure globules
 t float away into ! air1 ea* "o ( !m   
*>g$ ) a /ore ( pot5tial en]gy4 ,let u  
foll[ ?is vapor sph]ule z x floats into 
! upp] regions ( ! atmosph]e4 ,myriads (
 its fell[s travel ) x until x rea*es a 
po9t :]e cond5sation takes place1 :5 x  
collapses & unites ) o!r vapor p>ticles 
to =m wat] aga94 ,9 do+ ?is ! heat t 0  
exp5d$ ^u x to dis5gage x 7:e!r ! heat 0
 artificial or t ( ! sun's rays7 n[     
reappe>s ei!r z s5sible heat or z       
electricity1 or bo?4 ,& ?is is :at is   
meant 9 meteorology by lat5t heat becom+
 s5sible heat at ! "t ( cond5sation2 9  
fact1 x is /or$ or pot5tial en]gy becom+
 active or k9etic1 & assumes ! =m ( heat
 or electricity1 z be=e /at$4 ,we h ?us 
review$ ! matt] ( ! =ego+ *apt] 9 ord]  
to foll[ ! c\rse ( ! /or$ en]gy f !     
melt+ ( ! ice to ! vapor1 & back aga9 to
 wat]3 to d\bly impress ! fact t ! en]gy
 us$ 0 n consum$1 b /ill exi/s & is     
ready = fur!r "w4  ,dur+ ! progress ( a 

hail/orm1 x has be5 /at$1 "o ( ! factors
 t is active to produce ?is ph5om5on is 
! int5se asc5sional =ce t is giv5 to !  
moi/ure-lad5 air1 caus$ by int5se heat  
at ! surface ( ! e>?4 ,?is condition    
=ces ! moi/ure vapor to high] regions ( 
! atmosph]e ?an is ! case ) ! ord9>y    
?und]/orm4 ,ano!r factor t is und\bt$ly 
active 9 produc+ hail "u ^! circum/ances
 is t :5 cond5sation takes place 9 !    
high] regions1 & is !re=e m en]getic on 
acc\nt ( ! int5s] cold1 ! pot5tial en]gy
 t is set free by ! moi/ure sph]ules    
takes1 9 a l>g] degree1 ! =m (          
electricity r ?an heat1 z is ! case "u m
 ord9>y circum/ances4 ,:ile 9 ! end ?is 
electrical en]gy becomes active heat1 x 
does n = ! "t be+1 & ?us favors ! ready 
congelation ( ! cond5s$ moi/ure into    
hail/ones4 ,hail/orms are always att5d$ 
by incessant ?und] & lightn+1 & ?is fact
 favors ! !ory advanc$ above4  ,x w be  
easily se5 f a /udy ( ! =ego+ :at a     
wond]ful factor evaporation 7:i* is a   
product ( ! sun's rays7 is1 9 ! play (  

cele/ial dynamics4 ,x asc5ds f ! surface
 ( ! e>? or ocean lad5 ) a /or$ en]gy1 !
 p[] ( :i* no man c compute1 & beside   
:i* gravitation is a m]e po9t4 ,9 ! upp]
 regions ( atmosph]e ?is pot5tial =ce "u
 c]ta9 conditions is releas$ & becomes  
an active factor1 n only 9 ! =mation (  
cl\d & ! precipitation ( ra91 hail1 &   
sn[1 b x di/urbs ! equilibrium ( ! air &
 sets t 9 motion4  ,c]ta9 physici/s d5y 
t evaporation has any?+ to d )          
atmosph]ic electricity4 ,!y tell u t x  
is caus$ by ! arre/ ( ! en]gy ( !       
sunbeam by ! cl\ds & vapor 9 ! upp]     
atmosph]e4 ,we admit t a "p ( ! en]gy is
 s arre/$1 & is /or$1 = ! "t1 9 moi/ure 
globules by a process ( cl\d evaporation
 to transp>5t vapor aga94 ,yet ?is does 
n h9d] ! same process f go+ on at !     
surface ( ! e>? :]ev] !re is wat] or    
moi/ure4 ,b !y tell u t ! electroscope  
does n %[ any signs ( electrification 9 
! evaporat$ moi/ure4 ,( c\rse x does n4 
,! electroscope is n made to detect !   
pres5ce ( en]gy except :5 set free z    

electricity4  ,a w\nd-up spr+ does n    
seem to be electrifi$1 b if x is releas$
 ! en]gy /or$ 9 x w be trans=m$ into    
electricity if ! conditions are "r4 ,j  
s1 ! en]gy requir$ to put ! moi/ure     
sph]ule into a /ate ( /ra9 is lat5t     
until "s p[] releases x1 :5 x reappe>s z
 active en]gy ( "s =m4  ,we h n[ foll[$ 
! relation ( heat to wat] f a po9t #aj  
degrees bel[ freez+ up to :]e x 0 =c$   
into its orig9al gases1 oxyg5 & hydrog54
 ,^! gases h /or$ 9 !m a wond]ful am\nt 
( pot5tial en]gy4 ,:5 "o p\nd ( hydrog5 
& eight p\nds ( oxyg5 unite to =m wat] !
 me*anical value ( ! en]gy giv5 up at t 
"t 9 ! =m ( heat is repres5t$ by        
#dg1jjj1jjj p\nds rais$ to "o foot 9    
height4 ,& ?is is ! measure ( ! en]gy t 
0 put into n9e p\nds ( wat] to =ce x f a
 /ate ( vapor into its con/itu5t gases4 
,aft] ! comb9ation ( ! gases into a /ate
 ( vapor ! temp]ature s9ks to t ( boil+ 
wat]4 ,! am\nt ( en]gy giv5 up 9 cond5s+
 ! n9e p\nds ( vapor into n9e p\nds (   
wat] is equal to #f1gbj1jjj foot-p\nds4 

,if ?is n9e p\nds ( wat] is n[ cool$ f !
 boil+ po9t to #cb degrees ,fahr5heit we
 come to ! f9al fall1 :]e ! pot5tial    
en]gy t is /or$ 9 ! op]ation ( melt+ ice
 is giv5 up sudd5ly at ! mom5t ( freez+1
 :i* 9 n9e p\nds ( wat] is #iic1edf foot
 p\nds4  ,pr(essor ,tyndall1 9 speak+ ( 
! am\nt ( en]gy t is giv5 up betwe5 !   
po9ts :]e ! con/itu5t gases unite to =m 
n9e p\nds ( wat] & ! po9t :]e x congeals
 z ice1 says3 ,our n9e p\nds ( wat]1 at 
its orig9 & dur+ its progress1 falls d[n
 ?ree precipices--! fir/ fall is        
equival5t 9 en]gy to ! desc5t ( a ton   
weight d[n a precipice #bb1cbj feet     
high-ov] f\r miles2 ! second fall is    
equal to t ( a ton d[n a precipice #bijj
 feet high1 & ! ?ird is equal to a fall 
( a ton d[n a precipice #dcc feet high4 
,i h se5 ! wild /one avalan*es ( !      
,alps1 :i* smoke & ?und] d[n !          
declivities ) a vehem5ce almo/ suffici5t
 to /un ! obs]v]4 ,i h also se5         
sn[flakes desc5d+ s s(tly z n to hurt ! 
fragile spangles ( :i* !y are compos$4  

,yet to produce f aque\s vapor a        
quantity :i* a *ild c\ld c>ry ( t t5d]  
mat]ial dem&s an ex]tion ( en]gy        
compet5t to ga!r up ! %att]$ blocks ( ! 
l>ge/ /one avalan*e ,i h ev] se5 & pit* 
!m to twice ! height f :i* !y fell4  ,:5
 we contemplate ! =ego+ facts z relat$  
to s small an am\nt ( wat] z n9e p\nds1 
& multiply ?is result by ! am\nt ( sn[- 
& ra9fall ea* ye> & ! am\nt ( ice t is  
congeal$ & aga9 liquefi$ by ! p[] ( !   
sun's rays1 we are appall$1 & %r9k f !  
task ( attempt+ to r$uce ! am\nt ( en]gy
 exp5d$ 9 a s+le ye> to measurable      
units4  ,hav+ consid]$ wat] 9 its       
relation to heat 9 ! prec$+ *apt]s1 we w
 n[ take up ! subject ( wat] 9 its      
relation to ice & sn[fall & ! ph5om5a   
exhibit$ 9 ice riv]s1 commonly call$    
glaci]s4  ,:5 wat] is "u pressure !     
freez+ po9t is r$uc$ sev]al degrees bel[
 #cb degrees ,fahr5heit4 ,?is fact has  
be5 det]m9$ by conf9+ wat] 9 a close    
vessel & putt+ x "u pressure & subject+ 
x to a freez+ mixture1 & by ?is means   

det]m9+ ! freez+ po9t "u su* conditions4
 ,by putt+ a bullet or some?+ ( t nature
 into ! wat] t is subject$ to pressure  
"o c tell by %ak+ x :5 ! freez+ po9t is 
rea*$4 ,if wat] is put "u pressure &    
cool$ to a po9t bel[ #cb degrees1 & yet 
/ill rema9s 9 ! liquid /ate1 x may be   
sudd5ly congeal$ by tak+ (f ! pressure2 
?is %[s t ! pressure helps to hold !    
molecules 9 ! position necess>y = !     
liquid /ate1 & prev5ts ! re>rangem5t (  
!m t takes place at ! mom5t ( freez+4   
,:5 ! wat] molecules are arrang$ = !    
liquid condition !y may be comp>$ to a  
spr+ t is w\nd up & held 9 position by !
 heat en]gy t is /or$ 9 ! wat]4 ,& :5   
?is en]gy is giv5 up to a c]ta9 degree !
 p[] t holds ! spr+ w\nd up is sudd5ly  
releas$1 :5 x unw9ds & occupies a l>g]  
space4 ,!re is a =ce t we may call pol> 
=ce1 :i* is con/antly t5d+ to pu% !     
molecules ( wat] into an arrangem5t su* 
z we see :5 cry/allization takes        
place--z x always does 9 ! act ( freez+4
 ,^! pol> =ces _c act s long z ! en]gy 9

 ! =m ( heat is suffici5t to hold ! wat]
 9 ! fluid /ate4 ,b ! mom5t ?is en]gy1  
:i* t5ds to hold x 9 ! fluid /ate1 falls
 bel[ t :i* t5ds to re>range x into !   
cry/all9e =m1 x is ov]come by ! sup]ior 
p[] ( ! latt] =ce1 & we h ! ph5om5on (  
solidifi$ wat]4  ,a v int]e/+ exp]im5t  
may be p]=m$ ) a block ( ice by anyone  
:5 ! ice is ne> ! melt+ po9t4 ,if a wire
 is put ar\nd ! ice & a suffici5t weight
 is susp5d$ to x1 ! pressure ( ! wire on
 ! ice w gradually liquefy t portion    
imm$iately "u ! wire1 :i* all[s x to s9k
 into ! ice sl[ly1 & z ?is process goes 
on ! ice freezes toge!r aga9 beh9d !    
wire1 s t 9 "t ! wire w pass entirely   
?r\gh ! block & leave x /ill a solid    
block1 z x 0 be=e ! exp]im5t began4     
,?is is an int]e/+ fact :i* x w be well 
to rememb] :5 we come to expla9 glacial 
action1 or r ! law t gov]ns glacial     
action4 ,if we take two pieces ( melt+  
ice & br+ !m toge!r !y imm$iately       
congeal at ! po9t ( contact4 ,?is       
ph5om5on is call$ regelation4 ,ice has  

"s ( ! prop]ties ( a visc\s sub/ance4 ,x
 w yield sl[ly to pressure1 especially  
:5 ne> ! melt+ po9t1 b if put "u a      
t5sional /ra9 x w break1 z any brittle  
sub/ance w1 s t x has ! prop]ties ( bo? 
viscosity & brittl5ess4 ,ord9>ily we are
 9 ! habit ( treat+ wat] z a fluid & ice
 z a solid1 b f :at has gone be=e !     
read] mu/ und]/& t 9 a c]ta9 s5se ice   
%\ld be treat$ z hav+ semi-fluidic      
prop]ties4     ,,*apt] ,,xxiv4  ,,:y    
,,does ,,ice ,,float8   ,nature is full 
( surprises4 ,by a long s]ies (         
exp]im5tal inve/igations y ?9k y h      
e/abli%$ a law t is z unalt]able z ^? ( 
! ,m$es & ,p]sians4 ,b once 9 a :ile y  
/umble ^u ph5om5a t seem to contradict  
all t has gone be=e4  ,^!1 h[ev]1 may be
 only ! exceptions t prove ! rule4 ,x is
 recogniz$ z a fundam5tal law t heat    
exp&s & cold contracts2 t ! atom :5 9 a 
/ate ( int5se motion 7:i* is ! condition
 produc+ ! effect t we call heat7       
requires m room ?an :5 its motions are (
 a less amplitude4 ,9 o!r words1 an     

increase 9 ! amplitude ( atomic motion  
is heat+1 :ile a decrease is cool+4 ,x  
foll[s f ! above /atem5t t ! cold] a    
body becomes ! small] w be its          
dim5sions4 ,!re are two or ?ree1 &      
p]haps m1 exceptions to ?is rule1 & !   
mo/ notable "o is t ( wat]4 ,wat] foll[s
 ! same law t all o!r sub/ances d "u !  
action ( heat & cold1 )9 c]ta9 limits   
only4 ,if we take wat]1 say1 at #ej     
degrees ,fahr5heit & subject x to cold x
 w gradually contract 9 bulk until x    
rea*es #ci degrees ,fahr5heit4 ,at ?is  
po9t1 v curi\sly1 contraction ceases1 & 
"h we f9d ! maximum d5sity ( wat]4 ,if !
 temp]ature is /ill l[]$ we f9d ! bulk  
is gradually increas+ in/ead ( dim9i%+  
7z is ! rule ) o!r fluids71 & :5 x      
rea*es ! freez+ po9t !re is a sudd5 &   
m>k$ expansion1 s mu* s t a cubic foot (
 ice1 :i* is solidifi$ wat]1 w n weigh z
 mu* z a cubic foot ( wat] be=e x       
freezes--h5ce x floats4  ,let u try an  
exp]im5t4 ,take a small glass flask1    
t]m9at+ 9 a long neck1 say ( f\r to six 

in*es1 & ( small diamet]4 ,suppose !    
wat] 9 ! glass to be at #ej degrees     
,fahr5heit4 ,fill ! flask ) wat] until x
 /&s halfway up ! neck at #ej degrees   
temp]ature4 ,n[ imm]se ! flask gradually
 9 hot wat]1 & obs]ve ! effect4 ,= a    
mom5t ! wat] w l[] 9 ! neck ( ! tube1 b 
?is is due to ! fact t ! glass exp&s    
be=e ! heat is communicat$ to ! wat] &  
enl>ges its capacity4 ,b imm$iately !   
wat] w beg9 to rise z ! heat is         
communicat$ to x1 & w cont9ue to exp& up
 to ! boil+ po9t4 ,n[ take ! flask out (
 ! hot wat] & gradually introduce x into
 a freez+ mixture made ( brok5 ice &    
salt4 ,imm$iately ! wat] w beg9 to fall 
9 ! tube1 %[+ t x is contract+ "u !     
cold1 & x w cont9ue to contract until x 
rea*es a temp]ature ( #ci degrees       
,fahr5heit1 :5 x w come to a /&/ill & !n
 proce$ to exp& z ! temp]ature ( ! wat] 
l[]s4 ,:5 x rea*es ! freez+ po9t ! fluid
 c no long] rise 9 ! neck ( ! flask1 :i*
 is brok5 by ! sudd5 expansion t takes  
place at ?is po9t4  ,to %[ :at an       

irresi/ible p[] resides 9 ! atoms ( :i* 
! body is made1 let u take an iron flask
 ) walls "o-half in* or m 9 ?ickness2   
fill x ) wat] & seal x up by screw+ on !
 neck an iron cap2 n[ plunge x into !   
freez+ mixture1 & ! fir/ effect w be to 
contract ! wat] unless x is already bel[
 #ci degrees ,fahr5heit1 b :5 x rea*es t
 po9t expansion sets 91 :i* cont9ues to 
! freez+ po9t1 :5 a greatly increas$    
expansion takes place sudd5ly4 ,! walls 
( ! iron flask1 al?\gh a half-in* 9     
?ickness1 are no long] able to resi/ !  
comb9$ ef=ts ( ! billions ^u billions ( 
! atoms ( :i* ! wat] is made up1 9 _!   
individual clamor = m room1 h5ce ! flask
 is %iv]$ into pieces4  ,!re are "o or  
two o!r sub/ances :i* are exceptions to 
! g5]al rule1 b we w m5tion only "o1 :i*
 is ! metal bismu?4 ,if we %\ld melt a  
suffici5t am\nt to fill an iron flask1  
su* z we h describ$1 & subject x to !   
same freez+ process1 ! flask w be brok5 
! same z 9 ! exp]im5t made ) ! wat]4  ,a
 qu]y arises1 ,:y ?is ph5om5on8 ,:y does

 wat] foll[ a diff]5t law 9 cool+ f t ( 
ne>ly all o!r sub/ances8  ,?is is a case
 :]e x is mu* easi] to ask a "q ?an to  
answ] x4 ,:5 wat] solidifies at ! mom5t 
( freez+1 cry/allization sets 94 ,b :at 
is cry/allization8 ,cry/allization is a 
peculi> arrangem5t ( ! molecules (      
matt]1 :i* takes place 9 "s sub/ances :5
 !y pass f ! liquid to ! solid =m4 ,!   
molecules assume def9ite =ms & %apes1   
accord+ to ! nature ( ! sub/ance4 ,:5   
wat] assumes ! solid =m "u ! action (   
cold ! molecules arrange !mselves       
accord+ to c]ta9 def9ite & fix$ laws1 ! 
result ( :i* is to increase ! bulk to a 
consid]able ext5t ov] t :i* ! same numb]
 ( molecules w\ld occupy at a temp]ature
 ( #ci degrees ,fahr5heit4 ,h5ce1 z has 
be5 h]et(ore /at$1 a giv5 block (       
solidifi$ wat] is light] ?an ! same bulk
 w\ld be 9 ! fluid /ate1 & ?is is !     
reason :y ice floats4  ,:at w\ld happ5 9
 case nature did n make ?is exception to
 ! laws ( expansion & contraction by    
heat & cold1 9 ! case ( wat]8 ,fir/1 our

 lakes w\ld freeze f ! bottom upw>d2 z  
soon z ! surface became froz51 or ev5   
cold] ?an ! wat] und]nea?1 x w\ld drop  
to ! bottom1 ! w>m] wat] bel[ com+ up by
 a well-kn[n law--t ! w>m] fluid rises &
 ! cold] falls4 ,?is circulation w\ld   
cont9ue until ice began to =m1 :i* w\ld 
imm$iately drop to ! bottom1 & ?is      
process w\ld g on until ! :ole mass 7   
froz5 solid4 ,9 ! same way our riv]s 9 !
 nor!rn climates w\ld freeze f ! bottom1
 & 9 "t our valleys w\ld fill up ) ice  
to a ?ickness t ! summ]'s sun w\ld nev] 
melt1 & gradually all nor? ( a c]ta9    
zone w\ld become a great glaci]1 r5d]+ n
 only ! lakes & riv]s b also ! surface (
 ! e>? unfitt$ = animal life4  ,^? :o   
believe t ! laws ( nature are !         
creations ( a b5efic5t & all-wise       
,intellig5ce w see 9 ?is exception to ! 
g5]al law 9 ! case ( freez+ wat] a /rik+
 evid5ce ( design4 ,b ^? :o h no su*    
belief w say x is a mo/ =tunate ?\gh    
=tuit\s circum/ance 7a say+ !y w h to   
make1 reg>d+ ?\s&s ( o!r ?+s 9 nature71 

& g on fl\nd]+ 9 ! int]m9able sea ( ,i  
don't "k4  ,! atom :5 x is act+ "u !    
direction ( a fix$ law is a giant 9     
/r5g?4 ,& :5 its individual /r5g? is    
multipli$ by billions ^u billions !     
comb9$ en]gy ex]t$ produces a p[] t is  
irresi/ible4 ,n only has nature end[$ ^!
 atoms ) ?is wond]ful p[]1 b %e has also
 will$ t !y arrange !mselves 9 l9es (   
beauty4 ,9 confirmation ( ?is we ne$    
only to /udy ! "w ( ! fro/ ^u our w9d[  
panes4 ,z we lie 9 our b$s on a cold    
night & exhale moi/ure f our lungs x    
settles ^u ! w9d[ panes ( our b$rooms1  
:]e ,nature--t wond]ful arti/--=ms x    
into beautiful pictures t gladd5 our    
eyes :5 we awake3      ,mo/ beautiful   
?+s2 !re are fl[]s & trees1     ,&      
bevies ( birds1 & sw>ms ( bees1     ,&  
cities1 & temples1 & t[]s1 & ^!     ,all
 pictur$ 9 silv] %e54     ,,*apt] ,,xxv4
  ,,glaci]s4   ,glaci]s are riv]s ( ice1
 &1 l o!r riv]s1 "s ( !m are small & "s 
v l>ge4 ,!y fl[ d[n ! gorges f high     
m\nta9s1 ^: peaks are always cov]$ ) a  

blanket ( et]nal sn[4 ,summ] & w9t] !   
sn[ is precipitat$ ^u ^! m\nta9s1 & f "t
 to "t ! heat ( ! sun's rays s(t5s !    
sn[1 :5 by its great weight x packs m   
closely toge!r until x is1 9 _m cases1  
=m$ into solid ice-cakes4 ,if we take a 
quantity ( sn[ or a quantity ( granulat$
 ice & put x "u a suffici5t pressure we 
c produce cle> solid ice1 & x is by ?is 
process t ice is =m$ out ( ! sn[ & hail 
t falls cont9ually ^u ! tops ( ^!       
glacial m\nta9s4 ,we h se5 t ice        
possesses c]ta9 visc\s or semi-fluidic  
prop]ties & t x w yield to pressure1 b  
if we put x "u suffici5t t5sional /ra9 x
 snaps l glass or any o!r brittle       
sub/ance4 ,z ! sn[s ^u ^! m\nta9s pile  
up high] & high] ! pressure becomes     
great] & great] until x rea*es a po9t   
:]e ! mass beg9s to move gradually d[n !
 m\nta9 side1 foll[+ ! gul*es & defiles 
t furni% a pa? ( lea/ resi/ance to its  
fl[4  ,at ! sides & bottom1 :]e !re is  
contact ) ! e>?1 ! movem5t is sl[] ?an x
 is at ! surface & 9 ! middle ( ! ice   

/ream4 ,if !re 7 no curves 9 ! rav9e or 
gul* ?r\gh :i* x fl[s ! po9t ( greate/  
movem5t w\ld be conf9$ to ! middle ( its
 wid?4 ,b 9 fl[+ ?r\gh a w9d+ gul* ! mo/
 rapid fl[ foll[ ! l9es ( greate/       
pressure1 & ?is l9e is deflect$ f side  
to side1 s t ! l9e ( greate/ fl[ is m   
w9d+ ?an is ! bottom ( ! valley ?r\gh   
:i* x fl[s4 7,! movem5t is call$ a fl[1 
b x is v sluggi%1 only a few in*es 9 a  
day1 z w appe> lat]47  ,if ! bottom &   
sides ( ! valley 7 /raight ! surface ( !
 ice w\ld be comp>atively ev52 ,i say   
comp>atively1 = z comp>$ ) a smoo?      
surface x w\ld be v r\gh2 b !re w\ld be 
none ( ! great crevasses or op5+s n[ to 
be f\nd 9 ! ice1 :i* sometimes are v    
l>ge & ext5d to a great dep?4 ,if 9 its 
d[nw>d c\rse ! bottom ( ! rav9e sudd5ly 
becomes /eep]1 ! top ( ! ice is put "u a
 t5sional /ra9 :i* causes x to break1   
?us =m+ ! crevasses4  ,if at ! bottom ( 
! desc5t ! valley curves upw>d or       
pres]ves ! /raight l9e = a consid]able  
di/ance1 ^! crevasses w close at ! top &

 p]haps op5 at ! bottom1 & ! blocks (   
ice w freeze toge!r to su* an ext5t t ! 
wat] caus$ by ! melt+ ice w fl[ on top  
until x comes to ano!r crevasse1 :]e x  
runs ?r\gh to ! bottom or und]fl[1 :i*  
is always an att5dant ( a glaci]4  ,!   
glaci] cont9ues its fl[ d[n ! m\nta9    
side till 9 "s cases x rea*es q to !    
valley bel[1 & 9 o!rs x /ops %ort1 z !  
action ( ! sun is s great t x melts     
entirely away at ?is po9t z fa/ z x     
moves d[n4 ,9 ! w9t] "t1 h[ev]1 ! glaci]
 may fl[ f> d[n into ! valley & w       
accumulate greatly 9 bulk1 ow+ to ! fact
 t ! ice =ms f ! precipitation ( sn[ on 
top fa/] ?an x melts away und]nea?4 ,if 
x 7 n = ! fact t 9 summ] ! glaci]s melt 
fa/] ?an !y =m1 ! :ole valley w\ld 9 "t 
become a great riv] ( ice4 ,x is ! case 
9 ,switz]l& t "s ye>s ! accumulation is 
great] f sn[fall ?an dim9ution f melt+4 
,if ?is condition %\ld cont9ue x w\ld   
become a s]i\s matt]4  ,9 ! d[nw>d fl[ (
 a glaci]--sl[ z x is--!re is an        
exhibition ( wond]ful p[]2 great b[ld]s 

are torn f _! b$s & ei!r gr\nd to p[d]  
or c>ri$ d[n to ! end ( ! glaci]1 to be 
dropp$ ) ! o!r debris t has be5 c>ri$   
!re by ! same =ce1 =m+ an accumulation t
 geologi/s call ! mora9e4 ,( ^! mora9es 
we w speak m fully lat] on4  ,x 0 !     
privilege ( ! writ] "s ye>s s9ce to     
visit ! great glaci]s ( ,switz]l& & to  
"s ext5t /udy _! action4 ,"s riv]s h _! 
orig9 *iefly 9 melt+ glaci]s4 ,!y />t z 
ice riv]s & end 9 riv]s ( wat]4 ,!      
effects dur+ ! great ice age ( "s ( ^!  
glacial riv]s1 :i* are n[ ext9ct1 are v 
rem>kable2 we %all h occasion to ref] to
 !m :5 we come to treat ( ! glacial     
p]iod4  ,!re is a glacial riv] fl[+ :i* 
is f$ l>gely by ! great ,rhone glaci] 9 
,switz]l&4 ,! wat] f ?is riv] is almo/ z
 :ite z milk1 :i* is occasion$ by !     
gr9d+ action ( ! great ice blocks on !  
rock z x fl[s d[n ! sides ( ! m\nta94   
,^! glacial riv]s are mu* high] 9 summ]1
 ( c\rse1 ?an 9 w9t]1 "s ( !m hav+ n    
only an annual fluctuation1 b a diurnal 
"o4 ,! =m] is caus$ by ! cold ( w9t]1 & 

! latt] because x freezes to "s ext5t at
 night & *ecks ! fl[ ( wat]4 ,! diff]5ce
 betwe5 day & night 9 ^! high altitudes 
is v m>k$4 ,:ile x is extremely hot 9 ! 
sun1 x is cool ! mom5t we /ep into !    
%ade4  ,i rememb] walk+ across "o ( !   
glaci]s 9 ! ,alps1 call$ ! ,m] de       
,glace1 "o cle> day 9 summ]1 :5 ,i      
suff]$ s mu* f ! heat1 al?\gh /&+ ^u a  
sea ( ice1 t x 0 necess>y to c>ry an    
umbrella4 ,9 fact1 dur+ my /ay !re 0 a  
case ( sun/roke t occurr$ ^u ?is same   
glaci]4 ,?is int5se heat dur+ ! day     
melts ! surface ( ! ice1 :i* =ms /reams 
t run along on ! top ( a glaci] until !y
 come to a crevasse or riffle 9 ! ice   
riv]1 :]e !y plunge d[n & become a "p ( 
! glacial /ream t is fl[+ und]nea? !    
ice4  ,! spe$ at :i* ^! ice /reams fl[  
v>ies greatly ) ! size ( ! glaci] z to  
wid? & dep? & ! /eepness ( ! grade1 & _m
 o!r conditions4 ,9 its movem5t ! glaci]
 is con/antly b5d+ & freez+ & be+ torn  
asund] by t5sional /ra91 yield+ &       
liquefy+ at o!r po9ts by pressure1 only 

to freeze aga9 :5 t pressure is remov$4 
,?is1 tak5 9 connection ) ! friction ( !
 great ice b[ld]s1 produces a movem5t t 
is exce$+ly complicat$ 9 its actions &  
int]actions4  ,accord+ to ,pr(essor     
,tyndall's inve/igations1 ! mo/ rapid   
movem5t obs]v$ 9 ! glaci]s ( ,switz]l&  
is ?irty-sev5 in*es p] day at ! po9t (  
greate/ movem5t4 ,f ?is po9t ea* way !  
motion gradually dim9i%es until x rea*es
 ! sides ( ! glaci]1 :]e ! motion is n m
 ?an two or ?ree in*es4  ,! great ,nor? 
,am]ican glaci]s move at a mu* high]    
rate ( spe$4 ,we are indebt$ to ,dr4 ,g4
 ,fr$]ick ,wright1 au?or ( ,! ,ice ,age 
9 ,nor? ,am]ica1 :o sp5t a mon? /udy+ ! 
,muir glaci] 9 ,alaska1 = _m details    
conc]n+ t great ice riv]4 ,?is glaci]   
empties into ,muir ,inlet1 :i* is an    
(f%oot ( ,glaci] ,bay4 ,x is situat$ 9  
latitude #eh degrees #ej m9utes &       
longitude #acf degrees #dj m9utes we/ ( 
,gre5wi*4 ,! bay into :i* ?is glaci]    
empties is ab\t ?irty miles long & f    
eight to twelve miles wide4 ,?is bay1 ) 

its great glaci]1 has a sett+ ( gr&     
m\nta9 peaks4 ,i _c d bett] ?an to quote
 ! words ( ,dr4 ,wright :5 he describes 
! location ( ?is glaci]4 ,dr4 ,wright   
liv$ = a mon? 9 a t5t on ! edge ( ?is   
bay1 a %ort di/ance bel[ ! face ( !     
great glaci]1 :]e ! iceb]gs fell (f e   
few m9utes into ! deep wat]4  ,he says3 
,to ! s\? ! calm surface ( ! bay op5$   
outw>d into ,cross ,s\nd tw5ty-five     
miles away4 ,! isl&s dott+ ! smoo?      
surface ( ! wat]s bel[ u seem$ b specks1
 & ! gr& vi/a ( sn[clad m\nta9s gu>d+   
ei!r side ( ,*a?am ,/rait seem$         
gradually to come to a po9t on ! s\!rn  
horizon4 ,we/w>d t[>d ! ,pacific 0 !    
m>vel\s outl9e ( ! s\!rn portion ( ! ,/4
 ,elias ,alps4 ,! l(ty peaks ( ,crillon1
 #ae1ijj feet high1 & ,fair ,wea!r1     
#ae1ejj feet high1 ab\t tw5ty-five miles
 away & ab\t ! same di/ance ap>t1 /ood z
 s5t9els ov] ! less] peaks4  ,! ,muir   
glaci] might be lik5$ to a great inl&   
sea ( ice f$ by _m tribut>ies or ice    
riv]s4 ,x n>r[s up at ! po9t :]e x      

empties into ,muir ,inlet to #aj1ffd    
feet1 or a little ov] two miles4 ,an    
enorm\s pressure is ex]t$ at ?is po9t1  
:i* causes ! ice to fl[ 9 ! c5tral      
portion at ! rate ( ab\t sev5ty feet p] 
day4 ,!re is a cont9ual boom+1 l ! fir+ 
( a cannon1 go+ on1 caus$ by ! bur/+ (  
"s great iceb]g ei!r be=e x takes its   
f9al leap into ! wat] or at ! mom5t (   
its fall4 ,at ! po9t :]e ^! great       
iceb]gs drop (f into ! wat] !y /& l a   
solid wall #cjj feet above its surface4 
,dr4 ,wright says3 ,f ?is po9t !re is a 
con/ant succession ( falls ( ice into ! 
wat]1 accompani$ by l\d reports4        
,sc>cely t5 m9utes1 ei!r night or day1  
pass$ dur+ ! :ole mon? )\t our be+ />tl$
 ) su* reports2 & frequ5tly !y 7 l ?und]
 claps or ! boom+ ( cannon at !         
bomb>dm5t ( a besieg$ city1 & ?is ?\gh  
our camp 0 two & "o-half miles bel[ !   
ice front4444 ,repeat$ly ,i h se5 va/   
columns ( ice ext5d+ up to ! full height
 ( ! front topple ov] & fall into !     
wat]4 ,h[ f> ^! columns ext5d$ bel[ !   

wat] c\ld n be told accurately1 b ,i h  
se5 b]gs float+ away :i* 7 c]ta9ly #ejj 
feet 9 l5g?4  ,x is e/imat$ t ! cubical 
cont5ts ( "s ( ^! iceb]gs are equal to  
#dj1jjj1jjj feet4 ,?is great glaci] is  
f$ by ! con/ant precipitation ( sn[ ^u !
 sides & peaks ( ! high m\nta9s t       
surr\nd its va/ amphi!at]1 :i* is floor$
 ) iceb]gs4 ,wond]ful z ?is seems to u  
to-day1 x is sc>cely a microscopic speck
 ( :at exi/$ dur+ ! ice age all ov] !   
nor!rn "p ( ,nor? ,am]ica4  ,!re are _m 
o!r great glaci]s 9 ! m\nta9s ( !       
,pacific coa/4 ,"s ye>s ago ,i saw "o ( 
^! imm5se glaci]s 9 ,briti% ,columbia1 f
 a po9t call$ ,glaci] ,/ation1 9 !      
,selkirk ,m\nta9s1 on ! ,canadian       
,pacific ,railroad4 ,x 0 dur+ ! mon? (  
,augu/1 :5 all ( ! region 0 p]vad$ by a 
d5se smoke occasion$ by burn+ =e/s4 ,?is
 glaci] is a v %[y "o1 ow+ to ! /eepness
 ( ! side ( ! m\nta9 & its great bread?4
 ,all ! glaci]s t exi/ to-day are       
gradually rec$+1 & are de/9$ ev5tually  
to entirely disappe>1 unless !re is a   

*ange 9 meteorological conditions1 :i*  
"s sci5ti/s claim w be ! case if we only
 wait long en\gh1 :5 aga9 all ?is nor!rn
 c\ntry w be cov]$ ) a great ice %eet4  
,!re is no d\bt 9 reg>d to ! facts      
conc]n+ a glacial p]iod t mu/ h exi/$ 9 
! ages pa/4 ,to anyone :o has made a    
/udy ( ! subject !re is n want+ abundant
 evid5ce to prove t ?is nor!rn c\ntry 0 
at "o "t envelop$ ) a great ice %eet (  
enorm\s ?ickness4 ,! conditions t exi/$ 
to br+ ab\t su* a /ate ( ?+s h be5 !    
subject ( mu* speculation by            
philosoph]s1 b no "o1 z yet1 has arriv$ 
at any v satisfactory conclusion4 ,_m   
!ories h be5 advanc$1 "s ( !m n wor?    
consid]+1 :ile o!rs h _m ?+s t give !m a
 %[ ( plausibility4 ,b all ( !m h :at is
 said ( ! ,d>w9ian !ory1 a miss+ l9k4 ,x
 w be int]e/+1 h[ev]1 & also in/ructive1
 to "k :at c be said 9 favor ( a set (  
conditions t w\ld produce su* mom5t\s   
results4     ,,*apt] ,,xxvi4  ,,evid5ces
 ,,& ,,!ories ,,( ,,an ,,ice ,,age4     
,!re is abundant & unassailable evid5ce 

t at "o "t1 ages ago1 a va/ ice %eet    
cov]$ ! :ole ( ! nor!rn "p ( ,nor?      
,am]ica1 ext5d+ s\? 9 ,ill9ois to a po9t
 betwe5 latitudes #cg & #ch4 ,?is is !  
mo/ s\!rly po9t to :i* ! ice %eet rea*$4
 ,f ?is po9t ! l9e ( extreme fl[ runs (f
 9 a nor!a/]ly & nor?we/]ly direction4  
,! nor!a/]ly l9e is ?r\gh s\!a/]n ,ohio 
& ,p5nsylvania1 /rik+ ! ,atlantic ,ocean
 ab\t at ,new ,york1 !nce ?r\gh ,long   
,isl& & up ! coa/ ( ,massa*usetts4      
,nor?we/]ly x foll[s ! ,mississippi     
,riv] to its junction ) ! ,miss\ri1 :i* 
x crosses at a po9t "s miles we/ ( ?is  
junction1 foll[+ ! g5]al c\rse ( ?is    
riv] a little s\? ( x ?r\gh ! ,/ates (  
,miss\ri1 ,nebraska1 ,dakota1 &         
,montana4 ,! l9es1 especially !         
nor!a/]ly "o1 are v irregul>1 %oot+ out 
into curves & !n rec$+4 ,?is l9e (      
extreme ice fl[ is m>k$ by glacial drift
 s prom95tly t no "o :o has /udi$       
glacial action c d\bt = a mom5t :at 0 ! 
cause ( ^! deposits4 ,! l9e is call$ !  
t]m9al mora9e4 ,by exam9+ a map ( ,nor? 

,am]ica & trac+ ! l9e ( ! mora9e z we h 
describ$ x1 x w be se5 t ab\t two-?irds 
( ,nor? ,am]ica 0 at "o "t cov]$ ) ice  
to a great] or less dep?4 ,h[ deep1 is  
simply a matt] ( conjecture1 b 9 !      
c5tral portions ( ! great glaci]1 :]e 0 
! bulk ( sn[fall1 x mu/ h rea*$ a dep? (
 sev]al miles to acc\nt = ! enorm\s     
pressure t w\ld be requir$ to c>ry ! ice
 s f> s\?w>d4  ,b let u g back & def9e  
:at is meant by a mora9e4 ,a mora9e is a
 "n giv5 to ! deposits t are ( /one1    
gravel1 & e>? t h be5 c>ri$ along by !  
movem5t ( ! glaci]s & deposit$ at _!    
m>g9s1 sometimes pil$ up to great dep?s4
 ,! composition ( ^! mora9es is det]m9$ 
( c\rse by ! nature ( ! c\ntry ov] :i* !
 /ream ( ice is fl[+4 ,b[ld]s ( enorm\s 
size h be5 c>ri$ = hundr$s ( miles1 & ! 
exp]i5c$ geologi/ is able to exam9e any 
"o ( !m & tell u :]e its home 0 be=e !  
glacial p]iod4 ,mora9es are divid$ into 
diff]5t classes accord+ to _! position &
 con/itution4 ,! mora9e f\nd at !       
extreme limit ( ice-fl[ is call$ !      

t]m9al mora9e1 z be=e m5tion$4 ,^? t are
 f\nd inside ( ?is l9e & betwe5 two fl[s
 are call$ m$ial mora9es4 ,!re is a     
subdivision call$ kettle or gravel      
mora9es1 :i* are v prom95t 9 nor!rn     
,ill9ois & s\!rn ,wiscons91 & may be    
said to culm9ate 9 ! vic9ity ( ,madison4
 ,?is mora9e is a great deposit (       
gravelly soil4 ,:]e ?is mora9e exi/s !  
face ( ! c\ntry is cov]$ ) kettle holes 
( all sizes & %apes1 & 9 "s ( !m !re are
 small lakes1 :ile o!rs are dry4 ,!     
great *a9 ( inl& lakes t are f\nd 9     
s\!rn ,wiscons9 & nor!rn ,ill9ois 7 =m$ 
by deposits ( ice t _h be5 cov]$ by     
glacial drift1 gravel & o!rwise1 br\ght 
d[n & deposit$ ^u ^! masses ( ice :i*   
gradually melt$ away1 leav+ a depression
 at ! po9ts :]e !y lay1 :ile ! drift t 0
 pil$ ar\nd !m loom$ up & became ! %ores
 ( ! lake4 ,?is is sub/antially ,dr4    
,wright's !ory1 :o /udi$ ! =mation ( ^! 
kettle holes at ! m\? ( ! ,muir glaci]4 
,?is en?usia/ic glaciali/ has sp5t _m   
summ]s trac+ ! t]m9al mora9e ) its fr+e 

along ! l9es h]et(ore indicat$4 ,he is1 
!re=e1 entitl$ to speak ) au?ority on   
matt]s ( glacial action4  ,! "p ( !     
c\ntry t has be5 pl[$ ov] by ^! glaci]s 
is call$ ! glaciat$ area & ! re/ !      
unglaciat$4 ,! :ole ( ,nor? ,am]ica nor?
 ( ! l9e ( ! t]m9al mora9e t we h trac$ 
is a glacial region1 ) ! exception ( a  
few hundr$ squ>e miles *iefly 9         
,wiscons91 :]e ! ice seem$ to h p>t$ &  
pass$ ar\nd ?is area1 com+ toge!r aga9  
on ! s\? side ( x4 ,! ice probably did n
 rea* ! extreme limit t %[s glacial     
deposit1 b und\bt$ly ! effects ( x are  
se5 = "s di/ance to ! s\?1 ow+ to ! fact
 t dur+ ! "t x 0 melt+ great quantities 
( wat] fl[$ away f ! extreme edge ( !   
ice1 c>ry+ ) x m or less ( ! glacial    
drift1 :i* 0 deposit$ = "s di/ance to ! 
s\?4 ,:5 ! ice rec$$ x und\bt$ly paus$  
at diff]5t po9ts1 :]e x rema9$ /ation>y 
= a long p]iod ( "t4 ,i mean /ation>y at
 its edges1 = ! fl[ ( ice 0 cont9ually  
mov+1 b 9 its progress s\?w>d x came to 
a po9t :]e ! heat 0 suffici5t to melt ! 

ice z fa/ z x arriv$ at t po9t4 ,!      
on-mov+ ice 0 cont9ually br++ ) x !     
debris t x _h ga!r$ up at diff]5t po9ts 
on its j\rney1 s t x is easy to see h[  
^! mora9es c\ld accumulate to a great]  
or less dep? at ! m>g9 ( ! ice fl[1 :i* 
w\ld be det]m9$ by ! duration ( ! p]iod 
x rema9$ /ation>y4 ,?is1 h[ev]1 is only 
"o factor1 z ! surface ( ! e>? 9 "s p>ts
 ( ! c\ntry w\ld be m easily pick$ up & 
c>ri$ ?an 9 o!rs2 !re=e1 ! drift        
accumulat$ mu* m rapidly 9 "s sections  
?an 9 o!rs4  ,ano!r factor t 0 active 9 
! m rapid accumulation at c]ta9 po9ts 0 
! spe$ at :i* ! ice mov$1 & ?is w\ld be 
det]m9$ by ! pressure t 0 beh9d x1 & !re
 w\ld always be l9es ( unequal pressure 
exi/+ 9 su* a great glaci] z mu/ h exi/$
 :5 ^! mora9es 7 =m$4  ,z an in/ance ( !
 diff]5ce 9 ! glacial deposits t are    
made 9 diff]5t p]iods dur+ ! "t ( !     
melt+ ( ! great ice %eet we may comp>e !
 ,kettle ,mora9es ( ,wiscons9 ) ! clay  
deposit mix$ ) brok5 gravel t we f9d    
along ! we/ coa/ ( ,lake ,mi*igan4 ,^?  

^: homes are situat$ betwe5 ,w9netka &  
,waukegan on ! lake %ore h ! f\ndations 
( _! h\ses set 9 glacial drift t 0 %ov$ 
into position by ! ice dur+ ! glacial   
p]iod4  ,anyone :o makes an exam9ation (
 ! bluffs along ! %ore ( ?is lake w     
notice t !re is no /ratification :atev] 
to ! deposit su* z w always be f\nd 9 an
 unglaciat$ region4 ,go+ we/ f ! bluff a
 few miles we come d[n to ! prairie     
level1 :]e we f9d ! soil ( an entirely  
diff]5t nature4 ,! soil ( ! prairies (  
,ill9ois & ,i[a is probably to a great  
ext5t a wat] deposit4 ,x is ! k9d we f9d
 9 ! bottom ( a pond t has /ood = _m    
ye>s1 & x w\ld seem t at "s p]iod all   
?is prairie c\ntry ) ! black soil 0 !   
bottom ( a great lake4  ,! facts ( a    
glacial p]iod are beyond "q1 b :5 x     
occurr$1 & h[ x occurr$ are que/ions t  
_m h tri$ to answ]4 ,s f>1 all t we c   
say ( !m is t "s ( !m are %rewd guesses4
 ,! evid5ces adduc$ = det]m9+ ! "t1 are 
! erosion caus$ by riv]s & /reams s9ce !
 ice subsid$4 ,"s ( ! riv]s & outlets ( 

lakes _h _! c\rses *ang$ by ! action ( !
 ice1 s t :5 x subsid$ new wat] c\rses 7
 =m$1 & ! erosion t !y h produc$ f t "t 
to ! pres5t furni%es ! data = det]m9+ ! 
"t s9ce ! subsid5ce ( ! ice at any      
p>ticul> po9t4 ,= in/ance1 ,niag>a      
,falls 0 und\bt$ly at "o "t situat$ at  
,que5/[n1 a numb] ( miles bel[ its      
pres5t position4 ,& ! "t t x has tak5 to
 gr9d out ! great gorge t exi/s betwe5 t
 po9t & ! pres5t falls is approximately 
a measure ( ! "t t has elaps$ s9ce !    
subsid5ce ( ! ice at t po9t4 ,v>i\s     
e/imates h be5 made to det]m9ate ! rate 
( erosion4 ,! e>li] ones put ! "t at    
ab\t #ce1jjj ye>s4 ,b !re are lat]      
inve/igators :o make ! "t mu* %ort]1 n  
ov] #aj1jjj ye>s4  ,s mu* = ! "t2 b y   
ask ,:at ab\t ! occasion1 or cause8 ,?is
 is a "q t _m h attempt$ to answ]1 !re  
hav+ be5 eight or t5 !ories promulgat$ )
 reg>d to ! cause ( ! glacial p]iod1 b  
no "o ( !m is entirely satisfactory1 &  
only two or ?ree ( !m are des]v+ ( mu*  
discussion4 ,x is always int]e/+ to "k  

:at p ?9k1 h[ev]1 ev5 if we d n agree ) 
!m4  ,! fir/ !ory nam$ is t ! glacial   
p]iod is due to ! decrease ( ! orig9al  
heat 9 our climate4 ,?is !ory c be      
dismiss$ by say+ t ! planet 0 cool+ at !
 "t & has be5 cool+ ev] s9ce1 & t !     
reasons = an ice age are great] n[ ?an  
!n1 on t !ory4 ,ano!r !ory assumes t at 
"s =m] p]iod !re 0 a great] am\nt (     
moi/ure 9 ! atmosph]e2 :ile ?is ( c\rse 
w\ld be ! occasion = great]             
precipitation ( sn[1 x does n acc\nt = !
 *ang+ conditions t w\ld produce ! ice  
effect4 ,t !re 0 a preglacial p]iod !re 
is abundant evid5ce1 9 buri$ =e/s1 !    
fill+ up & *ang+ ( riv] b$s1 & o!r      
evid5ces t w be ref]r$ to fur!r on4 ,?is
 !ory1 unmodifi$ & /at$ broadly1 is n   
satisfactory4 ,ano!r way ( acc\nt+ = !  
glacial p]iod is ! *ange 9 ! di/ribution
 ( l& & wat]1 :i* is suppos$ to affect !
 di/ribution ( heat ov] ! e>?'s surface4
 ,!re is mu* 9 ?is !ory t comm5ds itself
 z plausible4 ,ano!r !ory supposes t !  
l& 9 nor!rn ,europe & ,am]ica 0 elevat$ 

to a high] level at t "t ?an x is n[4   
,o!rs attribute x to v>iation (         
temp]ature 9 space & ( ! am\nt ( heat   
radiat$ by ! sun4 ,! f9al !ory = acc\nt+
 = ! ice age is attribut$ to :at is t]m$
 ! precession ( ! equ9oxes4 ,9 %ort1 !  
precession ( ! equ9oxes means t !       
division betwe5 summ] & w9t] is *ang+   
gradually1 s t dur+ a p]iod ( #aj1ejj   
ye>s ! summ]s are gr[+ long] 9 ! nor!rn 
hemisph]e & ! w9t]s %ort]4 ,we are n[ 9 
! p]iod ( long summ]s1 b 9 ano!r #aj1jjj
 ye>s we %all be 9 ! p]iod ( %ort summ]s
 & long w9t]s4 ,?is diff]5ce ( "t betwe5
 ! w9t]s & ! summ]s is suppos$ to be    
suffici5t to *ange ! !rmal conditions   
suffici5tly to produce an ice age4  ,x  
is true t ! conditions n[ are v ev5ly   
balanc$1 s mu* s t 9 ,switz]l& ! glaci]s
 w increase = "s ye>s toge!r1 :5 !      
conditions w *ange1 caus+ !m to         
gradually rec$e4 ,sev]al ( ! !ories t h 
be5 advanc$ pres5t evid5ces t are       
entitl$ to c>eful consid]ation1 b none (
 !m c be said to be entirely            

satisfactory4 ,x is well kn[n t ! *ief  
factors 9 ! production ( glaci]s are    
moi/ure & cold4 ,cold alone is n        
suffici5t2 nei!r is moi/ure1 unless we c
 precipitate x 9 ! =m ( sn[4 ,cold is   
oppos$ to ! production ( moi/ure1 & ?is 
is a flaw 9 ! argum5t pres5t$ by ! la/  
!ory1 unless we c c\ple ) x ano!r set ( 
conditions :i* we w discuss lat]4  ,!   
solution1 if x is ev] rea*$1 is p]haps m
 likely to be f\nd 9 ! realm (          
meteorology ?an geology4  ,x is         
unnecess>y to *ange ! conditions (      
temp]ature or ! am\nt ( moi/ure n[ exi/+
 9 ord] to produce ! great glaci] aga91 
provid$ ?is moi/ure c\ld be precipitat$1
 en\gh ( x1 9 ! "r place z sn[4 ,=      
in/ance1 if 9 ,switz]l&1 :]e !          
conditions are ne>ly balanc$1 ! annual  
precipitation c\ld be slightly increas$ 
we %\ld h a condition t w\ld precipitate
 m sn[ 9 w9t] ?an w\ld melt 9 summ]4 ,& 
! glaci]s w\ld gradually accumulate 9   
size until !y w\ld fill ! valleys &     
gorges to ! same ext5t z =m]ly prevail$4

 ,!re only ne$s to be su* a *ange 9 !   
meteorological conditions z w cause a   
great] precipitation 9 t "p ( ! globe   
favorable to glaci]s1 z1 = in/ance1 9 ! 
nor!rn "p ( ,nor? ,am]ica t[>d ,alaska4 
,?is might be produc$ by a *ange 9 !    
conditions ( ! equatorial curr5t1 s t   
evaporation w\ld be m rapid 9 ! nor!rn  
,pacific ?an x n[ is4 ,:5 we consid] t  
evaporation increases 9 proportion z !  
heat increases1 we c see t heat is j z  
important a factor 9 ! production (     
glaci]s z cold4 ,if evaporation c\ld be 
increas$ 9 ! ,pacific ,ocean we/ (      
,alaska1 :i* w\ld be c>ri$ by ! w9d ov] 
! m\nta9s ^u ! l&1 & precipitat$ z sn[1 
! great glaci]s 9 t region w\ld beg9 to 
gr[ in/ead ( gradually rec$+1 z is !    
case at pres5t1 & ?is )\t any *ange 9 ! 
temp]ature ( ! _w z a :ole or 9 ! am\nt 
( heat receiv$ f ! sun4 ,"o c readily   
see h[ *anges 9 ! elevation ( ! bottom (
 ! ocean w\ld h su* an effect ^u !      
tropical /ream z w\ld ei!r increase or  
decrease ! temp]ature ( ! !rmal riv] t  

fl[s up ! we/]n coa/ ( ,alaska4  ,:atev]
 may h be5 ! cause t creat$ ! great ice 
age 9 ,nor? ,am]ica1 s t a %eet ( ice   
cov]$ consid]ably m ?an half ( !        
cont95t1 !re is no d\bt 9 reg>d to !    
fact ( ! exi/5ce ( su* an age1 & x w be 
int]e/+ to /udy "s ( ! physical *anges t
 h be5 made by ! ice at t p]iod on !    
surface ( ! glaciat$ area4     ,,*apt]  
,,xxvii4  ,,glacial ,,& ,,preglacial    
,,lakes ,,& ,,riv]s4   ,s9ce ! recession
 ( ! ice1 preglacial lakes h be5 fill$  
up & are n[ dry l&1 & riv] b$s h be5    
*ang$ s t new *annels h be5 cut & new   
lakes h be5 =m$4 ,ev5 ! imag9ation1 t   
wond]ful ar*itect1 ) all its t5d5cies to
 exagg]ation1 palls 9 its attempt to    
give expression 9 measur$ quantities to 
! mighty p[] ex]t$ by ! great glaci] or 
comb9ation ( glaci]s t exi/$ 9          
comp>atively rec5t times4 ,i say rec5t  
times1 because ev5 #aj1jjj ye>s is only 
a m]e po9t ( "t :5 comp>$ ) ! actual age
 ( our globe4  ,"s ye>s ago1 9 company )
 ,dr4 ,wright1 au?or ( ! ,ice ,age 9    

,nor? ,am]ica1 ,i visit$ ,devil's ,lake 
ne> ,b>aboo1 ,wis4 ,at ?is po9t are     
/rik+ evid5ces ( ! "w ( ! ice age4 ,be=e
 ! glacial p]iod ! ,wiscons9 ,riv] made 
a det\r "s miles we/ ( its pres5t *annel
 ?r\gh ! high hills 9 ! region (        
,b>aboo4 ,! hills on ea* side ( ,devil's
 ,lake are v precipit\s & are =m$ almo/ 
entirely ( rocks4 ,! riv] at t po9t     
pass$ betwe5 two ( ^! hills4 ,:5 ! ice  
fl[$ d[n x surr\nd$ ^! hills1 yet did n 
sweep ov] _! tops1 b left great piles ( 
glacial drift1 bo? at ! po9ts :]e ! riv]
 *annel ent]$ ! hills & :]e x em]ges f  
!m4 ,! *annel betwe5 ! hills 0 protect$ 
& n fill$ ) ! debris4 ,!re=e a deep bas9
 0 left1 :i* is kept fill$ by ! wat]%$  
furni%$ by ! surr\nd+ hills4 ,?is lake  
rec$es _m feet dur+ ! summ]1 b x is aga9
 fill$ up by ! ra9s & sn[s ( w9t]4 ,!re 
is no consid]able /ream ei!r fl[+ into  
or out f x4 ,x is a lake =m$ by !       
glaci]s1 b 9 a diff]5t way f ^? 9 !     
gravel deposits at o!r p>ts ( s\!rn     
,wiscons9 & nor!rn ,ill9ois4  ,!re are  

hundr$s & p]haps ?\s&s ( lakes t h be5  
=m$ 9 "o way or ano!r ?r\gh ! p[] (     
glacial action4 ,^! small] inl& lakes1 s
 _m ( :i* are se5 9 nor!rn ,ill9ois1    
s\!rn ,wiscons91 & ,m9nesota1 are due   
almo/ entirely to ! great deposits (    
glacial drift t h be5 transport$ ) !    
ice4 ,:]ev] ^! kettle holes are f\nd    
l>ge bodies ( ice h become an*or$1 :ile 
! ice beh9d x has c>ri$ ! drift until x 
is cov]$ ov] & pil$ up at ! sides4 ,:5  
^! ice m\nta9s melt$ away depressions 7 
left :i* 9 "s cases h result$ 9 lakes1 &
 9 o!rs simply dry kettle holes4 ,?is   
process has be5 h9t$ at 9 a =m] *apt]1 b
 we give x "h z "o ( ! k9ds ( lakes =m$ 
dur+ ! glacial p]iod4 ,!y are f\nd      
ev]y:]e t glacial action has prevail$4  
,!y are f\nd 9 great abundance 9 "s p>ts
 ( ,new ,engl& on ! m>g9 ( ! t]m9al     
mora9e4 ,^! lakes1 h[ev]1 are           
comp>atively insignificant z comp>$ ) ! 
great inl& seas l ,lake ,sup]ior & ,lake
 ,mi*igan1 t und\bt$ly owe _! orig9     
l>gely to ! ice age4  ,!re are o!r      

factors1 h[ev]1 t ent] into ! =mation ( 
! great *a9 ( lakes on ! nor!rn b\nd>y (
 ! ,unit$ ,/ates besides ^? m5tion$1 t h
 br\ght into exi/5ce ! small] inl&      
lakes4  ,glacial lakes may be divid$    
into ?ree classes4 ,^? f\nd 9 ! kettle  
holes ( ! t]m9al or m$ial mora9es1 & ^? 
t are =m$ by ! deposition ( ! glacial   
drift1 z1 = in/ance1 ,devil's ,lake1 &  
^? t are caus$ by ice =m+ dams across ! 
valley ( a riv] t la/$ only dur+ ! ice  
age4 ,9 "s lakes ( ! second class       
erosion und\bt$ly ent]$ into _! =mation 
z well z ! pil+ up ( glacial drift4  ,9 
ord]1 h[ev]1 t we may und]/& m fully !  
=mation ( ^! great] lakes x w be        
necess>y = u to g back & exam9e !       
conditions t seem to h exi/$ be=e !     
glacial p]iod4  ,x is a fact well kn[n t
 cont95ts h p]iods ( elevation &        
depression4 ,!re is abundant evid5ce t !
 nor!rn portion ( ! ,nor? ,am]ican      
cont95t 0 elevat$ to a mu* high] level 9
 preglacial times ?an x occupies n[4    
,?is is evid5c$ 9 v _m ways by s\nd+ !  

dep?s ( old riv] b$s n[ fill$ ) glacial 
debris4 ,! old b$s %[ unmi/akable       
evid5ces ( hav+ be5 worn d[n to _!      
pres5t level by ! action ( runn+ wat]4  
,!y also prove to be _m feet bel[ !     
pres5t sea-level4 ,?is fact seems to be 
suffici5t to prove ! !ory ( a high]     
elevation ( ! ,nor? ,am]ican cont95t 9  
preglacial times4 ,x %\ld be said "h t  
und\bt$ly ! con/ant fill+ up ( ! ocean )
 ! drift c>ri$ d[n by ! riv]s has       
some:at rais$ its level1 b h>dly to !   
ext5t indicat$ by ! old riv] b$s4 ,! "q 
naturally arises1 ,:]e did all ! dirt   
come f to fill up ^! great riv] b$s &   
*ange ! :ole topography ( ! nor!rn half 
( ! cont95t8 ,dr4 ,wright e/imates t !re
 is n less ?an #a1jjj1jjj squ>e miles ( 
t]ritory 9 ,nor? ,am]ica cov]$ ) glacial
 debris to an av]age dep? ( #ej feet4 ,(
 c\rse1 ! dep? v>ies 9 diff]5t places f 
a few in*es to sev]al hundr$ feet4 ,( ! 
c>ry+ p[] ( ^! great glaci]s we w speak 
m fully 9 a future *apt]4 ,9 preglacial 
times ! wat]%$ ( ! ,mississippi & ( !   

great riv]s ea/ ( ! ,alleghany ,m\nta9s1
 ! ,susquehanna & ,hudson1 ext5d$       
probably f>!r nor? ?an x does to-day4 ,!
 l>g] portion ( ! dra9age area t n[ f9ds
 an outlet ?r\gh ! ,riv] ,/4 ,lawr5ce at
 "o "t und\bt$ly dra9$ (f ?r\gh !       
,mississippi ,valley into ! ,gulf & !   
,valley ( ! ,mohawk into t ( ! ,hudson4 
,x is suppos$ by ^? :o h made ?is bran* 
( geology a /udy t prior to ! glacial   
p]iod a riv] fl[$ d[n ?r\gh ,lake       
,sup]ior1 :i* connect$ ) ,lake ,mi*igan 
at a po9t ne> its pres5t outlet at      
,sault ,/e4 ,m>ie1 ! *annel ( ! riv]    
pass+ d[n ?r\gh :at is n[ ! bottom (    
,lake ,mi*igan1 :i* _h an outlet at !   
head ( ! lake ne> ,*icago & fl[$ (f into
 ! ,mississippi ,riv]4 ,all ( ! lake    
bottoms ( ?is great *a91 ) ! exception (
 ,lake ,erie1 are n[ bel[ sea-level4 ,! 
reason = ?is exception w appe> fur!r on4
 ,be=e ! ice age !re 0 suppos$ to be no 
connection betwe5 ,lake ,mi*igan & ,lake
 ,huron1 z !re is n[1 ?r\gh ! ,/raits ( 
,mack9ac4  ,ano!r preglacial riv] _h its

 rise 9 ! region ( ,lake ,huron & fl[$  
?r\gh an old riv] b$ ext5d+ f !         
,georgian ,bay 9 a s\!a/]ly direction   
?r\gh ! prov9ce ( ,ont>io1 & empti$ into
 ! pres5t ,lake ,ont>io4 ,f ,lake       
,ont>io !re is an old riv] b$ runn+     
?r\gh ! ,valley ( ! ,mohawk :i* empties 
into ! ,hudson at ,troy4 ,nei!r ( ^! two
 riv]s1 hav+ _! s\rces 9 ! nor?1 f\nd an
 outlet ?r\gh ! pres5t ,/4 ,lawr5ce     
,riv]4 ,dur+ ! "t ( ! glacial p]iod !re 
is evid5ce t !re 0 m ?an "o c5t] ( sn[ &
 ice accumulation & ea* ( ^! great c5t]s
 probably _h sev]al subc5t]s4 ,?is !ory 
has color giv5 to x by ! directions (   
movem5t %[n by ! glacial drift4  ,!     
r\nd$ appe>ance ( b[ld]s 0 caus$ by !   
gr9d+ action ( ! ice4 ,^! b[ld]s1 :5 !y 
7 fir/ torn f _! rocky b$s by !         
irresi/ible p[] ( ice pressure1 7 r\gh &
 jagg$ 9 %ape1 ! same z any rock w\ld   
be1 torn f a qu>ry by a bla/4 ,!y h be5 
smoo!d & r\nd$ by rubb+ aga9/ ! mov+ ice
 & aga9/ ea* o!r 9 ! progress ( _! long 
j\rney f _! orig9al homes4 ,:]e _! home 

0 ! geologi/ c imm$iately tell ^u       
exam9ation4 ,x is only necess>y !n to   
exam9e ! b[ld]s ( any p>ticul> locality 
to det]m9e ! direction ( ! ice fl[ at t 
po9t4  ,!re seem to h exi/$ c5t]s ( ice 
accumulation to ! nor? ( all ( ! great  
lakes4 ,& :5 !y _h gr[n to a suffici5t  
height !y jo9$ at _! edges1 mak+ "o gr& 
glaci]1 ! movem5ts ( :i* 7 ! resultant (
 ! comb9$ pressure ex]t$ by ^! great    
c5t]s ( p[]1 s t all ( ,nor? ,am]ica    
nor? ( ! l9e ( ! t]m9al mora9e1 ) !     
exception ( a small area 7h]et(ore not$7
 *iefly 9 ,wiscons91 became cov]$ ) "o  
va/ %eet ( ice4  ,! glaci] nor? ( ,lake 
,sup]ior wid5$ out ! old riv] b$ by a   
process ( erosion to its pres5t wid?4   
,!re may h exi/$ some?+ ( a lake 9      
preglacial times1 ?r\gh :i* ! riv] ran1 
b x und\bt$ly owes its pres5t wid? to ! 
gr9d+ action ( ! irresi/ible iceb]gs & !
 pil+ up ( debris on ! %ores4 ,! riv] b$
 0 fill$ up by a glacial drift at ! po9t
 ( its pres5t outlet until ! lake 0     
rais$ 9 its level mu* high] ?an t (     

,lake ,mi*igan4 ,ano!r glaci] pl[$ d[n  
?r\gh ,lake ,mi*igan1 wid5+ x out to its
 pres5t dim5sions1 :ile ! glacial drift 
0 deposit$ at :at is n[ ! head ( ! lake1
 fill+ up ! old outlet & ?us mak+ a     
great dam4 ,! damm+ up ( ^! great wat]  
c\rses 0 ano!r cause = increas+ ! wid? (
 ^! lakes4 ,9 a simil> way ,lake ,erie 0
 =m$4 ,x is suppos$1 h[ev]1 t ?is lake  
is entirely ! product ( glacial action1 
z !re is no evid5ce ( an old riv] b$ 9  
its bottom2 besides1 x is mu* %all[] ?an
 ! o!r lakes4 ,! same action t =m$ ,lake
 ,erie fill$ up ! old riv] b$ runn+     
?r\gh ! prov9ce ( ,ont>io1 s t :5 ! ice 
rec$$ ,lake ,erie became ! new *annel = 
! old riv]4 ,! same process fill$ up !  
,valley ( ! ,mohawk to m ?an #ajj feet 9
 dep? & also rais$ ! ,valley ( !        
,hudson4 ,?is caus$ ! new *annel to be  
made ?r\gh ! ,niag>a ,riv] & a new r\te 
to ! ocean = ! dra9age ( all ! *a9 (    
lakes ?r\gh ! ,/4 ,lawr5ce4 ,x w be se5 
t ! bottoms ( all ( ^! great lakes to a 
c]ta9 ext5t 7 worn out by ! action (    

runn+ wat]1 except ,erie4 ,! great      
glaci]s wid5$ !m out1 & 9 ! case ( ,lake
 ,erie scoop$ x out4 ,at ! same "t x    
built great dams across ! outlets :i*   
rais$ ! surface ( ! wat] to a mu* high] 
level & caus$ !m to =m new outlets1 ?us 
*ang+ ! :ole face ( ! c\ntry ov] :i* !  
ice drift$4  ,! glaciat$ region ( ,nor? 
,am]ica is among ! mo/ productive 9 !   
_w1 & 9 _m respects pres5ts a mo/ pleas+
 l&scape4  ,o!r lakes besides ^! m5tion$
 h be5 =m$ dur+ ! ice p]iod ?r\gh block+
 ! c\rse ( a riv] by ! ice itself4 ,dr4 
,wright1 dur+ ! "t he trac$ out ! l9e ( 
! t]m9al mora9e1 discov]$ t ! ice %eet  
cross$ ! ,ohio ,riv] at a po9t ne>      
,c9c9nati1 :]e !re is a great b5d to !  
nor?w>d 9 ! riv]4 ,) ! exception ( ?is  
po9t & p]haps ano!r po9t bel[1 ! edge ( 
! great ice %eet kept a little nor? ( ! 
,ohio ,riv]4 ,at ?is po9t1 h[ev]1 ! ice 
seems to h fill$ ! valley f hill to     
hill1 :i* v naturally w\ld =m a great   
dam or lake 9 ! ,ohio ,valley4 ,( c\rse 
su* a lake c\ld n be p]man5t1 because1  

:5 ! ice melt$ away1 x aga9 op5$ !      
*annel & all[$ ! wat] to fl[ (f4  ,"s   
ye>s be=e ?is discov]y 0 made !re 7     
t]races f\nd along ! banks ( ! ,ohio    
,riv] & its tribut>ies t _h be5 !       
subject ( mu* speculation4 ,x is well   
kn[n t by ! action ( wat] f ra9fall1    
e>?1 gravel1 & o!r debris w wa% d[n !   
side ( a hill or m\nta9 until x /rikes a
 wat] level1 & !re x w build out a      
t]race ne> ! level ( ! wat] surface4 ,! 
wid? ( ^! t]races w be det]m9$ by ! "t !
 wat] has /ood at t level & ! ext5t &   
nature ( ! soil f :i* ! debris comes4 ,!
 evid5ces t are cit$1 pro & con1 w\ld   
fill a small volume1 b x is suffici5t to
 say "h t ! sum ( ! evid5ce goes to %[ t
 !re 0 an ice dam =m$ at a po9t ne>     
,c9c9nati & t x 0 ma9ta9$ = a           
consid]able p]iod ( "t4 ,t]races 7 =m$  
runn+ up ! ,ohio & its tribut>ies       
correspond+ to ! level t ! wat] mu/ h   
ris5 to if ! valley 7 fill$ up ) ice4   
,^! facts1 tak5 ) ! great] fact t ! ice 
%eet actually did cross ! ,ohio ,valley 

into ,k5tucky1 z is %[n by ! t]m9al     
mora9e1 seems to prove conclusively !   
exi/5ce ( su* a lake dur+ ! p]iod t !   
ice re/$ at its extreme limit4 ,! fact t
 9 "s places successive t]races are f\nd
 does n disprove ! !ory1 because x is m 
?an likely t :5 ! ice rec$$ x did s 9   
successive /ages1 rema9+ at diff]5t     
positions = a consid]able l5g? ( "t4    
,!re is abundant pro( ( ?is 9 !         
successive mora9es & also 9 ! =mation ( 
successive t]races4 ,"s ( ^! t]races    
c\ld h be5 =m$ f o!r causes4  ,x does n 
require any great /ret* ( ! imag9ation  
to und]/& h[ num]\s lakes1 mu* l>g] ?an 
any at ! pres5t day1 may h ext5d$ ov]   
l>ge portions ( ! ,we/ & ,nor?we/ dur+ !
 p]iod t ! ice 0 rec$+4 ,! ice did n /& 
) an ev5 ?ickness ov] ! surface ( !     
glaciat$ area1 b at "s po9ts x mov$ d[n 
9 great lobes1 :i* m>k$ ! l9es ( greate/
 pressure z well z ! greate/            
accumulation4 ,z ! ice melt$ away1 !    
?ick bodies ( ice might be _m1 _m ye>s 9
 melt+1 & !y might block ! outlet to a v

 ext5sive dra9age area & ?us =m a great 
inl& sea f ! va/ am\nts ( wat] t w\ld   
come f ! melt+ ice4  ,all ( ! region    
ab\t ,w9nipeg1 9 ! ,r$ ,riv] c\ntry1    
cov]+ great areas ( hundr$s ( miles 9   
ext5t1 is a level pla9 only lack+ !     
color+ to give to "o pass+ ?r\gh x !    
effect ( a great unruffl$ sea4 ,!re is  
no d\bt b t all ( ?is region 0 ! bottom 
( a great lake at "s p]iod :5 ! ice 0   
rec$+4 ,& ?is acc\nts = ! great dep? (  
black soil t we f9d 9 ?is & o!r regions4
 ,! soil 0 a wat] deposit1 su* z may be 
f\nd 9 ! bottom ( any %all[ lake or pond
 to-day1 & ?us _m ?\s& ye>s ago         
provision 0 made = ! f]tile areas :i*   
to-day are fe$+ ! _w ) :eat4  ,we c     
imag9e t dur+ ?is p]iod ! wat] t fl[$ (f
 ?r\gh ! great ,mississippi mu/ h be5 ( 
enorm\s volume z comp>$ to ! pres5t "t4 
,a l>ge portion ( ! delta ( !           
,mississippi :i* n[ is a "p ( ! ,/ates (
 ,l\isiana & ,mississippi 0 c>ri$ d[n   
dur+ ! ice-melt+ p]iod4 ,dr4 ,wright--z 
we h be=e /at$--has e/imat$ t !re are a 

million squ>e miles ( c\ntry t has be5  
cov]$ to an av]age dep? ( fifty feet )  
glacial drift4 ,a v l>ge am\nt ( ! e>? t
 0 spread ov] ! nor!rn portion ( !      
,unit$ ,/ates by level+ d[n hills &     
m\nta9s 9 ! nor!rn c\ntry & scoop+ out !
 great lakes has be5 c>ri$ mu* f>!r ?an 
to ! m>g9 ( ! ice %eet4 ,& ,i h no d\bt 
b t a great portion ( ,l\isiana & we/]n 
,mississippi is made ( e>? c>ri$ d[n    
l>gely dur+ ! p]iod ( melt+ ice &       
deposit$ 9 ?is great delta4  ,imag9e !  
effect t w\ld be produc$ by ! giv+ way (
 an ice dam or a great numb] ( !m at    
diff]5t p]iods1 t w\ld all[ a body (    
wat] z l>ge or l>g] ?an ,lake ,mi*igan  
to be dra9$ (f 9 a comp>atively %ort "t4
 ,:5 we ?9k ( x 9 ?is light ! great     
delta ( ! ,mississippi is easily acc\nt$
 =4  ,!re are evid5ces ( a great lake 9 
! ,r$ ,riv] c\ntry ( ! ,nor?we/ t is mu*
 l>g] ?an any ( our greate/ lakes4 ,!   
%ores ( ?is lake--! b$ ( :i* is n[ dry  
l& & ! he>t ( a great agricultural      
region--are well def9$ & h be5 survey$ &

 mapp$ out4 ,:5 ?is great body ( wat] 0 
releas$ x 0 to ! nor?w>d4 ,= ?is reason 
x 0 und\bt$ly held = a mu* long] "t ?an 
"s ( ! lakes to ! s\?w>d :]e ! ice melt$
 soon]4     ,,*apt] ,,xxviii4  ,,"s     
,,effects ,,( ,,! ,,glacial ,,p]iod4    
,!re is a wond]fully int]e/+ effect     
produc$ by ! action ( wat] dur+ !       
subsid5ce ( a glaci] at ,luc]ne1        
,switz]l&4 ,"s ye>s ago !re 0 discov]$  
"u a pile ( glacial drift at ! edge ( ! 
t[n ( ,luc]ne a numb] ( deep holes worn 
9 a great l$ge ( rocks t crop out at t  
po9t4 ,"o ( ^! pot-holes hav+ be5       
discov]$1 excavations 7 cont9u$ until a 
l>ge numb] ( !m 7 une>!d ( v>i\s %apes &
 sizes4 ,i _h ! pleasure ( inspect+ "s (
 !m 9 ! ye> #ahha4 ,!y are situat$ )9 an
 inclosure call$ ! ,g>d5 ( ! ,glaci]s4  
,"s ( ^! holes are tw5ty to ?irty feet 9
 diamet]1 & ! same dep?4 ,!re are o!rs t
 are small] 9 size1 b all ( !m possess !
 same g5]al *>act]i/ics4  ,9 ! bottom ( 
ea* "o 0 f\nd a b[ld]1 & 9 "o or two    
cases two ( !m4 ,! action ( ! wat] _h   

giv5 ^! b[ld]s a gyratory motion1 :i*   
gradually wore away ! rock und]nea?     
until r\nd holes 7 =m$ to ! size & dep? 
h]et(ore m5tion$4 ,:]e !re 0 only a s+le
 b[ld] ! holes 7 almo/ p]fectly r\nd1 b 
:]e !re 0 m ?an "o b[ld] ! holes 7      
sometimes 9 an oblong %ape4 ,! b[ld]s 7 
worn d[n to a v small size 9 mo/ cases1 
& 7 r\nd & smoo?4 ,! probabilities are t
 :5 ! action fir/ began ^! b[ld]s 7 l>ge
 & ( irregul> %ape4 ,!y mu/ h be51 9    
ord] to d ! enorm\s am\nt ( gr9d+ t "s (
 !m did to produce excavations 9 ! solid
 rock ) a diamet] ( ?irty feet & a dep? 
ab\t ! same4 ,! bottoms 7 r\nd l an     
old-fa%ion$ pot1 & ! insides poli%$     
p]fectly smoo?4 ,?is 0 purely an effect 
( ! tumbl+ ab\t ( ! b[ld]s by ! runn+   
wat] f ! melt+ ice ( ! great glaci] t   
cov]$ t region "s "t 9 ! long ago4  ,!re
 are o!r effects produc$ 9 rocks dur+ ! 
ice fl[ 9 ,nor? ,am]ica t are v int]e/+4
 ,great grooves are =m$ 9 ! rocks1 9 _m 
cases runn+ = long di/ances1 t h be5    
worn 9 by ! cutt+ p[] ( ! great ice %eet

 dur+ ! progress ( its movem5t4 ,!re is 
a great groove to be se5 at ,kelly's    
,isl& 9 ,lake ,erie4 ,x w be rememb]$ t 
?is lake is suppos$ to h be5 =m$        
entirely by ! ice ( ! glacial p]iod4 ,9 
its movem5t across ! c\ntry :i* is n[   
cov]$ by ! lake ! ice enc\nt]$ a huge   
rock =mation at ,kelly's ,isl&4 ,great  
,v-%ap$ grooves 7 cut ?r\gh ?is rock by 
! action ( ! ice1 deep en\gh = a man to 
/& 94 ,9 o!r places ! rock 0 plan$ (f 9 
! =m ( a great mold+1 a numb] ( feet    
wide1 ) ! same smoo?ness & accuracy z   
?\gh done by a ma*9e4  ,ano!r effect ( !
 glacial p]iod has be5 ! creation (     
num]\s wat]falls ?r\gh\t ! glaciat$     
area4 ,! mo/ notable in/ance is t ( !   
,falls ( ,niag>a4  ,9 preglacial times !
 b$s ( all riv]s & wat] c\rses _h worn  
d[n to an ev5 slope1 s t !re 7 v few1 if
 any1 wat]falls su* z we h to-day4 ,z we
 h be=e /at$1 ,niag>a ,riv] z well z !  
,/4 ,lawr5ce ,riv] is a new outlet = !  
dra9age ( ! great lakes4 ,a "p ( ?is    
dra9age =m]ly _h its outlet ?r\gh !     

,mohawk ,valley into ! ,hudson1 :i* is  
n[ fill$ up ) glacial drift4 ,! evid5ce 
is s conclusive t x is no long] d\bt$ t 
! ,niag>a ,riv] dates f ! "t t ! ice    
rec$$ f t po9t4 ,:5 ! wat] fir/ began to
 fl[ ?r\gh ?is new *annel x plung$ ov] !
 high rocky cliff at ,que5/[n1 & f t "t 
to ?is x has be5 we>+ its way back to ! 
pres5t position ( ,niag>a ,falls1 a     
di/ance ( ab\t sev5 miles4 ,a va/ am\nt 
( int]e/ c5t]s ab\t ?is riv] because x  
is ! be/ evid5ce we h ( ! "t t has      
expir$ s9ce ! glacial p]iod4 ,a great   
deal ( /udy has be5 giv5 to det]m9e !   
am\nt ( erosion at ! ,falls dur+ a ye>'s
 "t4 ,if ?is c\ld be accurately det]m9$1
 !n by measur+ ! di/ance f ! pres5t     
falls to ,que5/[n1 we c\ld easily       
det]m9e ! numb] ( ye>s s9ce ! ice p]iod4
 ,x is difficult to det]m9e1 = !        
conditions may h *ang$2 = in/ance1 !    
rock at ! ,falls to-day is said to be   
h>d] ?an x is fur!r d[n t[>d ,que5/[n4  
,! e/imates v>y f #ce1jjj ye>s to       
#aj1jjj ye>s--t is1 f a rate ( erosion (

 five feet to "o foot1 p] ye>4  ,e      
sci5ce is1 ne>ly or remotely1 relat$ to 
e o!r sci5ce4 ,if we c\ld det]m9e       
accurately ! date ( ! ice p]iod x w\ld  
settle a :ole lot ( o!r que/ions t are  
relat$ to x1 & "o ( !m is ! antiquity ( 
man4 ,_m /one implem5ts su* z 7 made &  
us$ by ! aborig9es h be5 f\nd at v>i\s  
times buri$ deeply "u ! glacial drift4  
,^! f9ds h occurr$ s (t5 t !re no long] 
rema9s a d\bt b t a race ( m5 exi/$ on  
?is cont95t 9 preglacial times4 ,!re are
 evid5ces t at a "t long ago ! temp]ate 
zone ext5d$ f> nor? ( ?is1 & x is n     
impossible t :at is n[ ! cont95t ( ,asia
 & t ( ,nor? ,am]ica 7 jo9$4 ,9 fact1 !y
 come v close toge!r to-day at ,b]+     
,/rait4 ,if su* 7 ! case ?is cont95t    
c\ld h be5 inhabit$ f ! old _w by an    
ov]l& r\te4 ,?is1 h[ev]1 is m]e         
speculation4 ,!re are a numb] ( factors 
t are tak5 into acc\nt 9 det]m9+ ! p]iod
 ( ! ice age besides ! ,niag>a ,riv] & !
 ,falls4 ,! ,falls ( ,/4 ,an?ony at     
,m9neapolis 7:i* l ! ,niag>a is a       

creature ( ! ice age71 ! we> ( wat] on !
 %ores ( ! great lakes1 ! newness ( !   
rocks t are pil$ up on ! t]m9al mora9es1
 all po9t to a mu* %ort] p]iod s9ce !   
ice age ?an x us$ to be suppos$1 &      
indicate t ! "t does n exce$ #aj1jjj    
ye>s4  ,to ! ord9>y m9d ! ice age no    
d\bt seems l a my?1 b to ! man ( sci5ce 
:o has made a /udy ( all ( ^! evid5ces x
 is z real z any fact 9 hi/ory1 & mu* m 
real ?an "s ( ! hi/ory we read4 ,9 ! =m]
 case we are deal+ ) evid5ces t appeal  
to our s5ses1 :ile 9 ! latt] we are     
deal+ ) ! recollections ( m5 conc]n+ :at
 purport to h be5 actual transactions1 &
 we "k en\gh ab\t ! human m9d to make x 
difficult sometimes to draw ! l9e betwe5
 ! actual & ! imag9>y4  ,! glacial p]iod
 is n only closely relat$ to !          
topography ( ,nor? ,am]ica & p>ts (     
,europe 9 ! *ang+ ( riv] b$s1 ! =mation 
( lakes1 ! transportation ( rock1 !     
gr9d+ d[n ( m\nta9s & spread+ ! debris  
ov] ?\s&s ( miles 9 ext5t1 b x is relat$
 9 an intimate way to _m ( ! sci5ces1   

su* z botany & zooelogy4 ,a /udy ( !    
flight ( animals & plants 9 front ( !   
great advanc+ ice %eet is a subject (   
int5se int]e/4 ,! migration ( great =e/s
 w\ld seem to be an impossible ?+ :5    
view$ f ! /&po9t ( a casual obs]v]4 ,x  
is true t individual trees c\ld n take  
!mselves up & move =w>d 9 advance ( !   
oncom+ ice1 b !y c\ld & did s5d _!      
*ildr5 on ahead1 & :5 ! ice _h ov]tak5 !
 *ildr5 !re 7 /ill ! *ildr5's *ildr5 ad 
inf9itum4  ,by an exam9ation ( ! map x w
 be se5 t ! l& ga!rs ab\t ! nor? pole1  
:ile ! s\? pole is surr\nd$ *iefly by   
great oceans4 ,z we h h9t$ be=e1 9      
preglacial times ! temp]ate zone ext5d$ 
mu* f>!r nor? ?an x does to-day1 & nor? 
( t !re 0 an arctic zone 7:i* to-day is 
l>gely cov]$ ) ice %eets71 :]e =e/s1    
plants1 & animals fl\ri%$ t 7 fitt$ = an
 arctic climate4 ,:5 ! glacial p]iod set
 9 & ! ice %eet began its s\!rn j\rney  
?is zone or climate 0 mov$ s\?w>d 9     
front ( ! ice1 ?us =m+1 z x 71 a mov+   
zone ^: climatic conditions 7 simil> to 

^? ( ! arctic regions 7at lea/ s f> z   
temp]ature 0 conc]n$7 9 preglacial      
times4 ,! ice movem5t 0 s gradual t "t 0
 giv5 = =e/s to spr+ up 9 advance ( x t 
mov$ s\?w>d at ab\t ! same rate z t ( ! 
mov+ ice4 ,und\bt$ly ! av]age movem5t 0 
v sl[ & 0 probably ?\s&s ( ye>s rea*+   
its s\!rnmo/ limit1 :i* is n[ m>k$ by ! 
t]m9al mora9e4 ,?us x w be se5 t :ile ! 
individual trees & plants c\ld n move1 !
 =e/ z a :ole c\ld4 ,x 0 gradually be+  
cut d[n on its nor!rn limit & z         
gradually x grew up on ! s\!rn limit ( !
 zone2 ! ice movem5t be+ s sl[ t ! "y   
tree ( to-day on ! s\!rn limit becomes a
 full-gr[n k+ ( ! =e/ by ! "t !         
rel5tless iceb]gs rea* x & cut x d[n &  
?us ! process w5t on until ! plants1    
trees1 & animals ( ! arctic region 7    
driv5 hundr$s ( miles s\? ( ! great *a9 
( lakes on ! nor!rn b\nd>y ( ! ,unit$   
,/ates4  ,_m ( ! animals ( preglacial   
times 7 unable to /& ! /ra9 ( !         
ev]-*ang+ climatic conditions & h become
 ext9ct1 b _! fossil rema9s are left to 

tell ! /ory to ! pres5t & future ages4  
,mu* ( ! hi/ory ( ^? times is a seal$   
book1 b ! p]sev]+ en]gy ( ! glaciali/ & 
ar*aeologi/ is gradually turn+ ! leaves 
( ?is old book & reveal+ new *apt]s ( ! 
wond]ful /ory ( ! ice4  ,z ! ice rec$$ !
 arctic zone aga9 travel$ nor?w>d1 & _m 
animals1 plants1 & trees t _h surviv$ ! 
vicissitudes ( ! ice age1 travel$ back )
 x4 ,"s ( !m1 h[ev]1 became acclimat$ & 
by adapt+ !mselves to ! new conditions  
rema9$ beh9d to live & gr[ ) ! aborig9es
 ( preglacial times4 ,"s ( ! plants &   
fl[]s t grew 9 pr(usion imm$iately "u ! 
edge ( ! great ice %eet 7 unable to live
 "u ! new conditions ( increas$ w>m?--t 
came ) ! retrograde movem5t ( ! ice--&  
ei!r _h to foll[ closely ! rec$+ ice or 
escape to high] altitudes1 :]e !y f\nd a
 cong5ial clime4 ,?us x is t we h arctic
 plants & fl[]s above ! timb] l9e & ne> 
! sn[ l9e ( our high m\nta9s4 ,9 pro( ( 
?is !ory x has be5 f\nd t ^! arctic     
plants d n exi/ ^u high m\nta9s1 su* z !
 ,peak ( ,t5]iffe1 :]e !y h be5 isolat$ 

f ! glaciat$ region4 ,! ,peak ( ,t5]iffe
 is situat$ on "o ( ! ,can>y ,isl&s1    
surr\nd$ by wat]1 s t !re 0 no possible 
*ance = ! arctic plants to seek refuge  
on ^! isolat$ elevations1 su* z !       
cont95tal m\nta9s furni%4  ,?us x w be  
se5 t ! progression & recession ( ! ice 
h n only =m$ great lakes1 *ang$ riv]    
b$s1 & cov]$ a million squ>e miles (    
area ) glacial drift av]ag+ fifty feet 9
 dep?1 mak+ _m wat]falls & giv+ v>iety  
to ! surface ( ! e>?1 besides produc+ ! 
f9e/ agricultural region 9 ! _w1 b h    
also giv5 v>iety to our =e/s & plants   
:]ev] ?is ice %eet has ext5d$4          
,,*apt] ,,xxix4  ,,dra9age ,,be=e ,,!   
,,ice ,,age4   ,we h already said t dur+
 ! ice age riv]-b$s 7 *ang$1 valleys 7  
fill$ up1 new lakes 7 made1 & wat]falls 
creat$4 ,great z 7 ! *anges made by !   
c>ry+ p[] ( mov+ ice1 /ill great] 7 ^?  
made 9 preglacial times2 n1 h[ev]1 f !  
action ( mov+ ice1 b f runn+ wat]4      
,erosion caus$ by runn+ wat] has1       
probably1 dur+ ! life ( ! _w1 transport$

 m mat]ial f place to place1 f m\nta9 to
 valley1 & f valley to ocean1 ?an any   
o!r ag5cy2 *iefly = ! reason t x has be5
 s mu* long] do+ its "w4  ,! valley ( ! 
,ohio ,riv]1 a ?\s& miles or m 9 l5g?1  
toge!r ) ! great numb] ( fe$]s t empty  
into x1 is an in/ance ( ! wond]ful      
erosive p[] ( runn+ wat]4 ,! valley ( ! 
,ohio ,riv] w probably av]age a mile 9  
wid? at its upp] level &1 deep z x is   
to-day1 x 0 mu* deep] 9 preglacial      
times4 ,!re is evid5ce t ! :ole b$ ( !  
riv] 0 f #ajj to #aej feet deep] ?an x  
is at pres5t4 ,?is has be5 det]m9$ by   
bor+s at diff]5t po9ts to asc]ta9 ! dep?
 ( ! drift t 0 lodg$ dur+ ! glacial     
p]iod 9 ! tr\gh ( ! ,ohio ,riv]4 ,anyone
 travel+ up or d[n ! riv] to-day c      
readily see t x is a great s9u\s groove 
cut d[n ?r\gh ! e>? by millions ( ye>s (
 wat] erosion1 & n only ?is1 b t at "s  
"t 9 its hi/ory ?is great valley has be5
 p>tly fill$1 =m+ on "o or bo? sides ( !
 riv] level areas--call$ bottom l&4 ,^! 
l&s are exce$+ly productive1 ow+ to !   

great dep? & ri*ness ( ! soil4  ,= _m   
ye>s ! writ] liv$ ^u "o ( ! riv]s       
tribut>y to ! ,ohio & (t5 made trips by 
/eamboat up & d[n ! ,ohio ,riv]4        
,travel+ along ?is riv] a close obs]v] w
 be /ruck by ! exactness ( !            
/ratifications 9 ! rock & 9 ! coal b$s  
to be se5 on ea* side ( ! riv]4 ,!y mat*
 z p]fectly z ! gra9 ( a block ( wood :5
 sawn asund]--%[+ t ^! coal b$s 7 =m$ at
 an age long be=e ! wat] cut ?is s9u\s  
groove4 ,:at ! wat] 0 do+ :ile ^! coal  
b$s 7 =m+ w be br\ght out 9 "s future   
*apt]4 ,all ! riv]s t are tribut>y to ! 
,ohio1 su* z ! ,monongahela1 !          
,alleghany1 ! ,musk+um1 ! ,t5nessee1 !  
,cumb]l&1 ! ,k5tucky1 ! ,waba%1 !       
,miami1 ! ,lick+1 ! ,scioto1 ! ,big     
,s&y1 ! ,kana:a1 ! ,hock+1 & ! ,great   
,beav]1 besides num]\s small] /reams1 h 
_! own valleys t h be5 worn away by !   
same process1 & to a great] dep? ?an !y 
n[ appe> to be4 ,all ( ! mat]ial t once 
fill$ ^! valleys has be5 c>ri$ d[n by ! 
wat] fill+ up ! bottom ( ! ocean &      

build+ out ! great delta ( ! l[]        
,mississippi4 ,m\nta9s h be5 worn d[n & 
c>ri$ away by ! action ( ! runn+ wat]   
until _! height is mu* l[] ?an 9 =m]    
times4 ,! great lakes1 t 7 enl>g$ dur+ !
 glacial p]iod & 9 "s cases :olly       
creat$--by ! scoop+ out & damm+ up ( !  
wat]ways & by pil+ glacial drift ar\nd  
_! %ores--h _h "s ( _! outlets rais$ to 
a high] level1 & o!rs h be5 creat$ anew4
  ,! old riv] b$s t =m]ly c>ri$ ! wat] t
 is n[ dra9$ ?r\gh ! ,/4 ,lawr5ce 7     
erod$ by ! action ( runn+ wat] to a     
great dep?1 z is %[n by num]\s bor+s    
along ! valley ( ! ,mohawk & d[n !      
,hudson4 ,! salt wells at ,syracuse1 ,n4
 ,y41 h be5 put d[n ?r\gh glacial drifts
 & ! salt wat] is f\nd 9 ! b$ ( ! old   
riv]4 ,great bodies ( salt are f\nd at t
 l[ level1 con/antly dissolv$ by ! wat] 
p]colat+ ?r\gh ! s& & gravel ( ! glacial
 drift4 ,?is salt wat] is pump$ up &    
evaporat$1 leav+ ! salt--=m+ "o ( !     
important indu/ries ( t region4 ,all ( !
 riv]s f ! ,ohio ea/w>d tell ! same     

/ory1 :i* is t at "s remote p]iod ! l& 0
 mu* high] above ! level ( ! sea ?an x  
is to-day4 ,! bottoms ( _m ( ^! old riv]
 b$s are l[] ?an sea-level1 b z !y 7    
made by runn+ wat] !y mu/ h be5 at "o "t
 above t po9t4  ,!re is abundant evid5ce
 t ! e>? s9ks 9 "s places & rises 9     
o!rs4 ,along ! ridges ( "s ( ! ea/]n    
m\nta9s are f\nd 9 great abundance !    
products ( ! bottom ( ! ocean4 ,^!      
evid5ces %[ t at "s p]iod1 :5 ! m\nta9s 
7 =m$1 a great convulsion ( nature rais$
 ! bottom ( ! ocean to ?\s&s ( feet     
above its level4 ,evid5ces ( ?is exi/ 9 
v>i\s p>ts n only ( ! ,unit$ ,/ates1 b (
 ! _w4  ,y ask1 ,if ?is erosion goes on 
& ! m\nta9s & hills are c>ri$ d[n &     
fill$ 9 to ! l[ places ( ! ocean1 :at is
 ! f9al de/9y ( ! e>? t n[ appe>s above 
! surface ( ! ocean8 ,evid5tly if ! e>? 
%\ld rema9 )\t fur!r upheaval1 at "s "t 
9 ! f>1 f> future ! l& w\ld gradually   
we> d[n & be c>ri$ (f into ! ocean & !  
ocean w\ld gradually rise1 ow+ to its   
re/rict$ area1 until x w\ld aga9 cov] ! 

:ole e>? z x und\bt$ly did at "o "t 9 ! 
e>?'s hi/ory4 ,?is fact ne$ n occasion  
any uneas9ess on ! "p ( ^? :o are liv+  
to-day or = millions ( ye>s to come4  ,!
 problem ( build+ a _w & !n te>+ x to   
pieces is a v complicat$ "o4 ,!re is a  
con/ant battle go+ on betwe5 ! p[]s t   
build up & ^? t te> d[n2 & ?is is z true
 ( "*-build+ z x is ( _w-build+4 ,! _w  
has nev] be5 exactly alike any two      
successive days f ! "t its f\ndations 7 
laid to ! pres5t mom5t4 ,x seems to be a
 fundam5tal law ( all life & gr[?1 z    
well z ( all decay1 t !re %all be a     
con/ant *ange4 ,!re is no su* ?+ z re/ 9
 nature4 ,! smalle/ molecules & atoms ( 
matt] are 9 con/ant agitation4 ,9 !     
animal & vegetable _w !re is a p]iod (  
life & gr[?1 & a p]iod ( decay & dea?2 &
 ?is seems to be ! de/9y ( planets      
!mselves z well z ! ?+s t live & gr[ ^u 
!m4 ,/ill1 sci5ce tea*es u t ) all ?is  
turmoil & *ange no?+ ei!r ( matt] or    
en]gy is lo/1 b t x is simply und]go+ "o
 et]nal r\nd ( *ange4 ,does ?is law     

apply to m9d & s\l8 ,d we die8 ,or d we 
simply *ange8         99       99       
99       99       99  ,nature's         
,miracles3  ,,famili> ,,talks ,,on      
,,sci5ce4  ,by ,,pr(4 ,,eli%a ,,gray4   
,,vol4 ,i4--,_w ,build+ & ,life3 ,e>?1  
,air & ,wat]4  ,,vol4 ,,ii4--,en]gy &   
,vibration3 ,=ce1 ,heat1 ,light1 ,s\nd1 
,explosives4  ,,vol4                    
,,iii4--,electricity & ,magnetism4      
,eli%a ,gray is a "n kn[n & honor$ by   
sci5tific m5 ! _w ov]4 ,f>m]'s boy1     
blacksmi? appr5tice1 %ip-jo9]1 c>p5t]1  
self-support+ ?r\gh a college c\rse2 8  
g5ius int]e/$ him 9 electricity1 & 9 t  
realm 8 ,inv5tions h made him fam\s4    
,^!1 ) 8 organization & presid5cy ( !   
,congress ( ,electricians at !          
,columbian ,fair ( #ahic1 & 8 _m        
decorations & degrees1 conf]r$ at home &
 abroad1 all /& sponsors = 8 fame4  ,^! 
little volumes convey sci5tific tru? )\t
 te*nical t]ms1 & are enri*$ )          
rem9isc5ce1 anecdote1 & reflections t   
allure & hold ! int]e/4       ,! place  

held by ,eli%a ,gray 9 ! sci5tific _w   
has      be5 won n by cat]+ to !        
applause ( ! public1 b      by a life   
devot$ to orig9al inve/igation 9        
untrodd5      fields4--,*icago          
,times-,h]ald4   ,h&y ,volumes1 #d-a_/b 
x #f-a_/d2 ,clo?2 #fj c5ts p] ,volume4  
,,=ds1 ,,h[>d1  ,,hulb]t1 #dg ,ea/ #aj? 
,/41 ,new ,york4         99       99    
99       99       99  ,,bits ,,( ,,ore  
,,f ,,ri* ,,m9es4  ,,! ,,nuggets        
,,s]ies4        ,don't ,worry ,nuggets3 
,f ,epictetus1 ,em]son1 ,george         
,eliot1 ,rob]t ,br[n+4 ,ga!r$ by ,jeanne
 ,g4 ,p5n+ton4      ,portrait ( ,em]son4
  ,might be m>k$ ,multum 9 ,p>vo4444    
,h>dly a p>agraph t does n br+ a new    
s5se ( /r5g? & com=t4--,*icago          
,int]-,ocean4       ,patriotic ,nuggets3
 ,f ,frankl91 ,wa%+ton1 ,jeff]son1      
,web/]1 ,l9coln1 ,bee*]4 ,ga!r$ by ,john
 ,r4 ,h[>d4      ,portrait ( ,wa%+ton4  
,a peculi>ly sugge/ive1 readable1 useful
 comp\nd ( great hi/oric ?\ghts f !     
greate/ ,am]icans4--,d5v] 7,col47       

,republican4       ,educational         
,nuggets3 ,f ,plato1 ,ari/otle1         
,r\sseau1      ,h]b>t1 ,sp5c]1 ,h>ris1  
,butl]1 ,eliot4 ,ga!r$ by ,john ,r4     
,h[>d4 ,portrait ( ,plato4  ,no tea*]1  
no p>5t1 & no ?\ghtful p]son likely to  
become ei!r "o or ! o!r1 b w\ld b5efit  
deeply by scann+ & he$+ ^! admirable    
selections4--,! ,exam9]1 ,new ,york4    
,philosophic ,nuggets3 ,f ,c>lyle1      
,rusk91 ,*>les ,k+sley1      ,amiel1    
,ga!r$ by ,jeanne ,g4                   
,p5n+ton4--,portrait (      ,c>lyle4  ,a
 h&y book1 conta9+ ma/] ?\ghts f ma/]   
m9ds1 is a desirable companion1 /imulat+
 9 ?\ght & action4--,sunday-,s*ool      
,times4  ,uni=m size & /yle3 #c-e_/h by 
#e-c_/h2 flexible clo?1 gilt top2 #dj   
c5ts p] vol4   ,,=ds1 ,,h[>d1  ,,hulb]t1
 #dg ,ea/ #aj? ,/41 ,new ,york4         
99       99       99       99       99  
,by ,,h5ry ,,w>d ,,bee*]4        ,bible 
,/udies3 ,read+s 7,g5esis to ,ru?71 )   
famili>      ,comm5t4 ,edit$ by ,j4 ,r4 
,h[>d4 ,clo?1 #a4ej4       ,a ,book (   

,pray]3 ,invocations1 ,pray]s be=e      
,s]mon1 &      ,clos+ ,pray]s f         
unpubli%$ notes ( ,t4 ,j4 ,ell9wood4    
,clo?1 #ge cts42 clo?1 gilt1 #a4jj4     
,com=t+ ,?\ghts3 ,= ,b]eavem5t1         
,illness1 &      ,adv]sity4 ,compil$ by 
,ir5e ,ov+ton4 ,vignettes4 ,clo?1       
limp1 #ge cts42 clo?1 gilt1 #a4jj4      
,bee*] z a ,humori/4 ,wit & ,humor f 8  
,works4      ,compil$ by ,elean ,kirk4  
,clo?1 #ge cts42 clo?1 gilt1 #a4jj4     
,a ,book ( ,pray]1 ,com=t+ ,?\ghts1     
,bee*] z a      ,humori/4 ,uni=mly b\nd1
 9 a box1 #b4be4       ,orig9al ,plym\? 
,pulpit1 #ahfh to #ahgc4 ,t5 vols4      
7orig9ally #be4jj7 9 ,five ,volumes4    
,clo?1 #ab4ej1 net4       ,plym\?       
,pulpit4 ,new ,s]ies4 ,f\r volumes1     
#ahgc-gd4 ,clo?1      p] vol41 #a4ej4   
,evolution & ,religion4 ,"p             
,i4--,!oretical2 pap]1 #ej cts4      ,"p
 ,,ii4--,practical & ,vital2 pap]1      
#a4jj4 ,b\nd 9 "o      vol4 ,clo?1      
#a4ej4       ,patriotic ,addresses3     
,slav]y1 ,civil ,w> 7) ! ,spee*es      9

 ,engl&1 #ahfc71 & ,civil ,lib]ty 9 !   
,unit$ ,/ates1      #ahej-he4 ,) a      
,review ( 8 ,life1 ,p]sonality1 &       
,public      ,influ5ce1 by ,john ,r4    
,h[>d4 ,portraits4 ,clo?1 #b4jj4        
,yale ,lectures on ,prea*+4             
,i4--,p]sonal ,elem5ts2                 
,,ii4--,social & ,religi\s ,ma*9]y2     
,,iii4--,*ri/ian      ,doctr9es4        
,?irty-?ree ,lectures4 #ifj pages4 ,?ree
 vols4 9      ,"o4 ,vellum clo?1 #b4jj4 
,life ,( ,jesus ! ,*ri/4 ,complet$      
,edition1 #b vols41      ,illu/rat$4    
,clo?1 #c4ej4 ,ei!r vol41 s+ly1 clo?1   
#a4ge4 ,! #b vols4 9 ,"o                
7,frontispiece71 #b4jj4       ,lectures 
to ,"y ,m53 ,on ,v>i\s ,important       
,subjects4 ,clo?1      #a4ej4           
,royal ,tru?s4 ,report$ f 8 ,spok5      
,words4 ,f\r?      ,am]ican f ,six?     
,engli% ,edition4 ,clo?1 #a4be4         
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